#337 - Insulin resistance masterclass: The full body impact of metabolic dysfunction and prevention, diagnosis, and treatment | Ralph DeFronzo, M.D.
Episode Stats
Length
2 hours and 26 minutes
Words per Minute
178.23076
Summary
Dr. Ralph DeFranzo is a distinguished diabetes researcher and clinician known for his pivotal work in advancing the understanding and treatment of type 2 diabetes. He is widely recognized for his groundbreaking contribution to the concept of insulin resistance, which has reshaped the understanding of Type 2 diabetes and its progression.
Transcript
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Hey, everyone. Welcome to the Drive podcast. I'm your host, Peter Atiyah. This podcast,
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of the subscription. If you want to learn more about the benefits of our premium membership,
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head over to peteratiyahmd.com forward slash subscribe. My guest this week is Dr. Ralph
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DeFranzo. Ralph is a distinguished diabetes researcher and clinician known for his pivotal
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work in advancing the understanding and treatment of type 2 diabetes. He's widely recognized for his
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groundbreaking contribution to the concept of insulin resistance, which has reshaped the understanding
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of type 2 diabetes and its progression. He played a very important role in bringing metformin to the
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United States as a standard treatment for the disease nearly 40 years ago, along with the
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discovery and development of SGLT2 inhibitor, a class of drugs you have no doubt heard me discuss
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many times before. With over five decades of research in the field, Dr. DeFranzo has received numerous
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prestigious accolades, including the Banting and Claude Bernard Awards, the highest honors that can be
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given to a diabetologist. This episode with Ralph is really a masterclass in the organ-specific aspects,
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the pharmacology, the diagnosis of type 2 diabetes, and it draws from his vast experience. Now, if you
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listen to my conversation with Jerry Shulman a few years ago on insulin resistance, what amazed me was how
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little overlap there was, not because the information is not congruent, but because of how much we were able
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to go into different topics. So the discussion with Jerry Shulman, which I would encourage everyone to
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listen to if they have not, really focused on one of the areas that insulin resistance manifests itself,
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which is in the muscle. What we talk about here is about all of the other organs. Spoiler alert, there are
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seven that are impacted by this condition, and therefore we go into much greater detail. They're in addition
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to the pharmacologic interventions, and I just have to say I learned more in this podcast than I do in
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most podcasts. It's one of the few that I had to immediately go back and listen to, and my notes
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from this podcast are so voluminous that they even provided substrate for internal meetings with our team
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in the practice. In short, there are many things that I've taken away from this that will directly impact
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my patients. Just as far as some of the other things we discuss, we get into details about how
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insulin resistance impacts liver. We do talk about muscle, but we talk more about fat cells. We talk
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about his development of the euglycemic clamp, something that some of you have probably heard of
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as the gold standard for measuring insulin resistance. Again, we talk about the pharmacology,
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not just the SEL22 inhibitors, but the GLP-1 agonists, metformin, and another class of drug that we
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don't talk about that often that, frankly, for me was a real eye-opener. There's a lot more I can say,
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but I think at the end of the day, you just kind of got to listen to this one maybe twice.
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So without further delay, please enjoy my conversation with Dr. Ralph DeFranza.
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Ralph, thank you so much for coming down to, I guess, up to Austin from San Antonio. Very excited to sit
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down with you and talk about potentially one of the most important subject matters in all of health.
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People who listen to me all the time hear and are familiar with me talking about these four horsemen,
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cardiovascular disease and cerebrovascular disease, cancer, neurodegenerative and dementing diseases.
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And then there's this fourth horseman that I talk about, and it's in many ways the squishiest
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because it's not the one that shows up on the most death certificates, but in many ways it's the
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foundational one that is amplifying the risk of all of those other causes of death. And I refer to it
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as metabolic disease spanning the spectrum from hyperinsulinemia to insulin resistance to fatty
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liver disease all the way out to type 2 diabetes. So given how much I speak about that, it seems very
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important that we should have a really thorough discussion of that foundational metabolic disease and
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no one better than you to have that discussion. So let's start a little bit with just telling
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folks briefly about what you're doing at UT San Antonio and why you've spent the last 40 plus,
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almost 50 years now working on this problem. Yeah, more than 50 years. I actually have been
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in this field of metabolic disease for a long time. I think I'm the longest consecutively funded 53
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years NIDDK investigator. I actually started even long before that when I was a medical student at
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Harvard, I had this fantastic teacher, Professor Cahill, who gave us all of the lectures on
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intermediary metabolism. And I decided this is what I wanted to do. And I worked each summer with Professor
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Cahill. And sometimes in life, you meet the right person, the right opportunity, it changes everything
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you do. And basically what I do now, I contribute directly to George. And when I gave the Banting lecture
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in 2008, people usually put a picture of their mother and father and children. And I love my
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mother and father and children, but I only showed one picture and that was Professor Cahill because
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he's really the person who's ended up directing me to where I am today.
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People who are listening, who are particularly astute might recall, I've referenced a number of
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Cahill's papers, but one of the more interesting studies he did, which it's possible he did while you
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were even a student there, was the 40-day starvation study. Now, you might've not been quite at Harvard
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yet because this was, if I recall, in the mid-60s, maybe 66, 67. And it was probably a group of medical
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students that actually volunteered, if not medical students, undergrads. They did a water-only fast
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for 40 days. And the study basically just followed all of the metabolites, what happened to glucose
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levels, obviously insulin, beta-hydroxybutyrydocetoacetate. Anyway, it was very fascinating stuff.
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One of the things that was most interesting to me in that study was even under a period of such
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extreme starvation, the brain never gave up its dependency on glucose. So even though ketone bodies
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began to service the brain by about day seven to 10 as the majority of the fuel, even at three and
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four weeks of starvation, glucose was, if my memory serves me correctly, still providing about a third
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of the brain's energy. Your memory is very good. The brain did switch over to ketone metabolism.
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And believe it or not, I didn't do the 40-day fast, but I was one of the people who fasted for
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five to seven days. If you fasted for three days, you could get paid $50. And I thought I was the
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richest guy in the world from this study. I can assure you that the physical specimens in this study
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were phenomenal. What did the 40-day fasting students get? I don't know, but I'm sure he paid
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them a lot of money. That's amazing. In order to do that. The interesting thing about that is you
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realize that we have so much energy stored in the human body. Who would have thought that you're a
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lean type person, you can fast for 40 days. But the real problem is at some point, you start to break
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down muscle. And then if you start to break down cardiac muscle, then prolonged fasting at that point
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becomes a problem. But you have a lot of energy stored in fat and you can starve for a long time.
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And obese people easily can go for three, four months with all the reserves that are in the body.
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Let's maybe talk a little bit about what insulin resistance is. We'll get into what causes it,
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but let's just maybe define for people this term that gets thrown around constantly. And let's
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explain what it is from a technical standpoint. Basically, every time you eat a meal and your blood sugar
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level goes up, you're going to release insulin. And insulin is sort of a master regulator for all
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biochemical processes in the body. One of the things that insulin is going to do is going to
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talk to your muscles. They're going to say, take up glucose and burn that glucose. What we need to know
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is in a normal person, when I infuse insulin, how much of the glucose is taken up by the muscle.
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And then we could look at someone who is, say, overweight, or we could look at someone who's
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diabetic. And I actually developed the gold standard technique, which is the insulin clamp
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technique to look at this. So we could take an obese person or a diabetic or a normal person,
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we raise the insulin. And then I'm using muscle as an example, how much glucose is taken up,
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disposed of by the muscle. And then I can compare if you're overweight compared to the lean person.
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Obese people are very insulin resistant in terms of muscle glucose uptake. I could look at the
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diabetic. They're even more insulin resistant. But there are many processes that insulin control.
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So insulin regulates how much fat is released from your fat cells. And obese people, unfortunately,
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insulin keeps the fat in your fat cell. But in obese people, insulin doesn't work so well.
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So instead of keeping the fat in the fat cell, even though your insulin is high,
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you're breaking down the fat. So you have to look at each individual process that insulin
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is controlling. And so for that process, we know this is what a normal person should respond like.
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This is what a diabetic responds like. And the diabetic is much, much more insulin resistant.
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They're not responding. In a certain way, it's a general term because insulin controls so many
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things. Protein metabolism. Insulin is very important in helping you to build protein.
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So I could infuse insulin. And we've done this using carbon labeled leucine. And we can define
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how insulin promotes protein metabolism in a normal, healthy person. And then I could do the
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same kind of study in an obese person. And we know that the obese people don't respond to the
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insulin as well in terms of aggregating protein metabolism. So it's kind of a general term.
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Does that translate not just to structural proteins such as enzymes or cellular structural
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proteins, but also macro structural proteins such as muscle?
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Absolutely. So I can look at specific enzymes within the cell. I can look at certain genes within
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the cell that are turned on or off. Or I can look at muscle in terms of muscle as a bulk. So there are
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many ways in which you could define insulin resistance. But basically, whatever the particular process
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you're looking at, you're comparing what would be the normal response in a normal, healthy person
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compared to what might happen in a diabetic person or an obese individual.
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So one of the challenges with the term insulin resistance is, as you said, it's a vague term and
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it's nonspecific because the actions of insulin are so many. It has an action in the liver. It has an
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action in the muscles. It has an action with response to glucose. It has an action with response to
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amino acids. And it has an action with response to fat, both in the liberation of fat, lipolysis,
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We'll go through all of these. But let's maybe start with how the euglycemic clamp test is done.
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Let's assume that I'm a healthy enough individual that we can use me as a proxy. I come into your
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clinic. What are we going to do? How do you run this test?
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Let me bring you back in time when I was a fellow because at that time, we didn't really have a good
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measure of insulin sensitivity. So what people would do is you do an oral glucose tolerance test
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and the insulin level would go up. Some people would say, I'll look at how much insulin comes out
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compared to the rise in glucose. And that's a measure of beta cell function. And then someone
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would just turn it around and say, look, I'm going to see how much the rise in glucose was per insulin.
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And that's a measure of insulin resistance. And it was very clear to me, well, this is insane.
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You can't take two variables and then just depending upon how you want to look at them,
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switch denominator and numerator. So I said, we need to develop something that is really more specific.
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Just to be clear, Ralph, I mean, unfortunately, we as clinicians are not able to do euglycemic clamps.
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We are still looking at oral glycemic tolerance tests. We are still giving people
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oral glucose and sampling glucose and insulin every 30 minutes and trying to impute what we can,
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which I'd love to come back and talk about interpretation, but carry on with the limitation.
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We actually have done a lot of work on how you interpret that. So what we said is,
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why don't we develop a serious way? And so we developed a technique where I could take a hundred
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people and I would infuse insulin initially as a primary dose and then just clamp the insulin
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level. So I give a prime continuous insulin infusion. I can take a hundred people and all
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hundred people, I can raise your insulin level by a hundred micro units per ml. And I can do that
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for two hours. And now I know that the stimulus, the insulin stimulus, whether you're lean, whether
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you're obese, or whether you're diabetic, whatever particular process that I want to look at.
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So maybe I wanted to look at how insulin shut down hepatoclucose production. And actually we were
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the first people to ever use radioisotopes to trace this and show that in normal people, insulin
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shut down glucose production by the liver very quickly. But obese people and diabetics were very,
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very resistant to the insulin. And then we said, we wanted to know, look, everybody now has got the
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same insulin level. How effectively does that insulin stimulate muscle glucose uptake? And again,
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what we showed, and these actually were the very first unequivocal demonstration that diabetic people
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type two were insulin resistant. Before this, there was a lot of controversy. Dr. Reven, who is a father
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of insulin resistance, I like to think I'm the son of Dr. Reven. He's a great idol of mine. He really
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was one of the very first people to insinuate that diabetics were insulin resistant. With the insulin
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clamp, we showed this very definitively. And we also know we use the label glycerol and free fatty
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acids, and we could show the ability of insulin to shut down release of lipid from the fat cell was
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markedly impaired. So three of the major organs, all of this work originally was done by us when I was
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back at Yale. Let's summarize those again. We're talking about this in an insulin sensitive person,
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right out of the gate. Insulin is going to shut down hepatic glucose output. Absolutely.
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Which again, all of this kind of makes sense if you think through the pathway. Our liver is constantly
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putting glucose into circulation because the muscles can't put glucose into circulation. So
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something has to feed the brain. If insulin is high, it suggests glucose is already sufficiently high.
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So let's not create more glucose toxicity. Let's shut that. Second thing it's going to do
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is it's going to take that excess glucose and put it in the place where we have the largest capacity
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to store it, which is muscle. So point two is we increase muscle uptake of glucose. And then point
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three you said was it's going to shut down lipolysis. It's going to shut down the release of triglycerides
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and or free fatty acids from the adipose tissue. That's very critical. We also, when we did these
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studies, we would put a catheter in the hepatic vein and in a femoral artery and a femoral vein. So we
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could look at the individual tissues. And what we showed is that when you infuse insulin, say 80 or 90
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percent of the glucose is going to be taken up in muscle. Only 10 percent is going to be taken up in
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the adipocyte and stored. How much in the liver? Basically none. Under euglycemic conditions, and we
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were the first to show this conclusively as well, there's no glucose uptake in the liver by insulin.
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Just explain to people what a euglycemic condition is.
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Euglycemic means you're fasting glucose when you wake up in the morning is 80. Now you're euglycemic.
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That means when we do the studies, we keep your fasting glucose of 80. We don't let the glucose
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change. All we're going to do is raise the insulin. And that means you're giving glucose.
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Of course, because if we didn't give glucose, then your blood sugar level would drop and then you'd
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release cortisol, you release epinephrine. I just want to make sure people understand that. I was going to
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come back to that. I wanted you to finish that point. So let's make sure we go back to the test
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because it's very counterintuitive. So I've got a catheter in each arm. I walk in off the street.
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I've been fasting. My blood sugar is 80 or 90, whatever milligrams per deciliter it is.
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You are going to have to infuse both insulin and glucose into each of my arms. And the reason is
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when you said a moment ago, you're going to steadily increase my insulin and take it to a steady state
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of 100 IU per mil. That's a staggeringly high insulin level.
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Not so high. In your life, after a meal, it would be maybe 60. Obese people very commonly get to 100.
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Sure, sure. For a healthy person, you would never see an insulin level that high. And if you were not
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simultaneously running glucose into them, you would kill them within minutes.
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Yeah. But to get to the point, they would become so profoundly hypoglycemic that they would cease to
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exist. And it should be obvious that if you're very sensitive to insulin, I have to infuse a lot
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of glucose. But the other beauty of it, as I said, when I was a young guy at Yale, there was a physician
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in New York, Dr. Altshuler. He was the first one to use trigated glucose to trace metabolic pathways.
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And I said, this is astounding. So I actually went to visit Dr. Altshuler and learned how he did it.
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So all of the insulin clamp studies that we did, we were the first people to use trigated glucose
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in humans. And to show that the ability of insulin to shut down the release of glucose from the liver
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Sorry to interrupt, but just to make sure that people are following us, the reason you wanted
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to use trigated glucose there was not to quantify the total amount of glucose disposal. You could do
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that on mass balance. You wanted to determine the ultimate fate of glucose. How much became hepatic
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glycogen, if any? Sounds like the answer is none. How much became muscle glycogen? Sounds like you said
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about 90%. And how much ultimately got converted through de novo lipogenesis into adipocyte or free
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fatty acid? Sounds like that's about 10% under the euglycemic condition. Is that correct?
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Yeah. In general, that's correct. Except in the muscle, remember,
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some of the glucose is going to be oxidized. So if you look at the glucose, once it gets into the
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cell, one third would go through the glycolytic pathway and be oxidized.
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Yes. And the other two thirds would be stored as glycogen.
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I mean, presumably you're doing this test and a person is sedentary.
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Is muscle that metabolically active at rest? I guess it is.
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Yeah. So that's really interesting. Does that mean you're increasing energy expenditure under these
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Well, of course, in a certain way you are, but it's not like when you go out and you exercise and you
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run a mile or two. So I would say you are turning on a number of cycles, which are, of course,
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going to increase energy expenditure. You're generating ATP. So there is a certain increase
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in energy expenditure. But if I really want to increase energy expenditure, I'd get you to go jog
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five miles or so because exercise is really the thing that really increases energy expenditure.
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And Ralph, just for a sense of amount, if you're doing this in, say, somebody my size who's
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insulin sensitive, how many actual grams of glucose would you be able to get into the person
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within the hour whilst keeping insulin clamped?
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So I'm going to do it first in terms of rates, the way we express it, and then I'll translate that.
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Under basal conditions, you wake up in the morning and your liver is producing and your tissues
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are taking up about two milligram per kilogram body weight per minute.
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Liver is producing, that's hepatic glucose output.
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That's hepatic glucose output, two milligram per kilogram body weight per minute. And we were the
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first to actually show this many years ago, and this is humans. Mice are very, very different,
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totally different. And that's why extrapolating from mice to humans can be a problem.
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Let's just reflect on that for a second. People who listen to this podcast are probably sick of me
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saying this, but I'm sorry. I just can't stop saying it. The liver never ceases to amaze me.
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It's an unbelievable organ. And again, I come back to this idea. It's the only major organ for
00:21:13.020
which we don't have extracorporeal support. If your heart, if you went into cardiogenic shock
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and we felt we could reverse it in time, we could put an intra-aortic balloon pump in you. We could put
00:21:23.740
an IABP in you. We could put a left ventricular device in you to stem you over until we get you out of
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there. If your kidneys are destroyed, we can transiently dialyze you. Even if your brain is
00:21:35.460
experiencing swelling, we can, you know, put enough steroids in you or decompress your skull
00:21:40.220
to give you the time to recover and keep you alive otherwise. Go through all the major organs. If
00:21:45.340
your spleen is dinged, take it out. Even if you lost your small bowel, we could at least transiently
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keep you alive with TPN or something like that. None of this is true with the liver.
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You know, in the old days, they actually used to use pig liver perfusion.
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But that was in the old days. We don't do that anymore.
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So the fact that the liver can titrate this amount is remarkable. So two milligrams per kilogram
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per minute. So you take an individual who weighs a hundred kilograms, you're putting 200 milligrams
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per minute of glucose into circulation. Then you can multiply that by however minutes you want to
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look. So that's a gram every five minutes. That's 12 grams of glucose every hour that the liver is
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putting out. But now when I do an insulin clamp, depending on how much I raise the insulin and over
00:22:41.120
the years, we've done a dose response curve. And I can come back to this because your fat is
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exquisitely sensitive to insulin. If I raise the insulin just by 10 micro units per ml, the fat
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stops producing free fatty acids and glycerol. You inhibit lipolysis literally completely. The liver,
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you need to get the insulin up to about 50 micro units per ml to really get it shut down.
00:23:09.060
Tell me, these people, when they come in unhealthy, they're what, they're at 5 to 10 faster?
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Yeah, they're at 5 to 10. So I'm going to raise them from 5 to 10 to maybe 15 or 20.
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And that's going to, in large part, shut down lipolysis. In fact, all of this sort of work
00:23:22.780
was work that we originally did many, many years ago. Now, at the level of the liver,
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you really need to get up to about 50 micro units per ml. So maybe at 10, I'm going to bring you up
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to 50. And that's in large part going to shut off glucose production by the liver. Now, that's
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critical because you wake up in the morning and your liver's producing glucose. Now, if you eat a
00:23:44.920
meal, glucose is coming in from the gastrointestinal tract. You can't have glucose coming in from the
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liver at the same time. Otherwise, you get very hyperglycemic. So when you eat a meal and that
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insulin comes out, it really needs to shut down a pad of glucose production. Now, what's replacing the
00:24:00.940
liver is what's coming from the meal. But then after you absorbed all of the meal, the liver needs
00:24:05.320
to turn back on. So understanding how the liver is responding to insulin is really very important.
00:24:11.600
And then if I want to look at what's going on in the muscle, the reason why we go to 100
00:24:16.100
micro units per ml, which is above physiologic, but it's still within the physiologic range.
00:24:21.740
If you really want to stimulate muscle glucose uptake completely in a normal healthy person,
00:24:26.720
you'd probably have to get the plasma insulin to about 200 micro units per ml.
00:24:34.340
You have now maximized muscle glucose uptake. In reality-
00:24:40.860
Just to make sure I understand what you're saying, you're saying that if you took an insulin
00:24:43.980
sensitive individual at 100 units of insulin versus 200, you will actually drive more glucose
00:24:52.600
uptake. You haven't saturated the GLUT4 transporter at 100.
00:24:56.620
Probably about 25% more uptake as you go from 100 to 200.
00:25:01.040
And these are all early studies that we did. So when we talk about insulin resistance, that's why I said
00:25:06.960
you need to know which tissue you're talking about and which metabolic pathway. And if you want to talk
00:25:12.720
about enzymes, you need to talk at what specific enzyme because insulin resistance needs to be
00:25:18.940
related to the tissue you're talking about and the process within the tissue that you're talking
00:25:24.220
about. So insulin resistance is a very important concept, but you all have to be a little bit more
00:25:30.420
specific about what aspect you want to address. So you can have insulin resistance in the fat cell.
00:25:36.620
You can have insulin resistance in the liver. You can have insulin resistance in the muscle. And then
00:25:41.060
something that's now pretty exciting, you may have insulin resistance in the brain.
00:25:45.000
And the suggestions now, and there are many insulin receptors in the brain. Jesse Roth,
00:25:51.000
very famous diabetes person, maybe 50 or 60 years ago was the first to describe insulin receptors in
00:25:57.320
the brain. And this is an area that's now starting to unfold. It may have some relationship to
00:26:02.740
neurodegenerative disease, Alzheimer's disease. Some people say that Alzheimer's disease is diabetes type
00:26:09.200
three. Brain diabetes. Yes. So insulin resistance is a very important concept. Let's say we're going
00:26:16.940
to talk about diabetes. Even though there's an ominous octet that I developed that's used everywhere in
00:26:22.720
the world for the pathophysiology of type 2 diabetes, if we really wanted to solidify it and say,
00:26:28.820
what are the two big concepts? Insulin resistance would be here. On the other hand,
00:26:33.620
would be impaired beta cell function. So if you are insulin resistant and your beta cells work well,
00:26:40.560
they know how to read the insulin resistance. They'll make enough insulin. You won't become
00:26:45.200
diabetic. Hyperinsulinemia can damage you in other ways, but you won't become diabetic. But what happens
00:26:51.380
is if you're insulin resistant, particularly if you have a genetic predisposition, if your beta cells
00:26:56.580
have to continuously pour out insulin, they start to exhaust. And insulin resistance is a disaster for
00:27:03.040
someone who has a genetic predisposition, it's going to bring out the diabetes. Insulin resistance,
00:27:08.720
in my opinion, is intimately related to cardiovascular disease. That is why when you see a diabetic patient,
00:27:15.720
10% of them, you walk in, you have diabetes, first time I see you, 10%, 15% of the people already have
00:27:21.780
clinically significant cardiovascular disease. And if you look carefully, virtually 100% of them do.
00:27:27.980
And sorry, Ralph, do you think that that is a result of the hyperinsulinemia or the untreated
00:27:33.760
or poorly treated hyperglycemia? All of the above. More importantly, what we showed, and we were,
00:27:39.620
again, the first people to show this, and the cardiologists, they're hemodynamically oriented,
00:27:48.740
But if you look at the insulin signaling pathway, insulin has got to bind to its receptor. And then
00:27:54.400
there's a signaling pathway. I can tell you all the molecules in there, which I'm not. And then
00:27:58.600
glucose gets transported in the cell. We were the first people to show in humans that that pathway
00:28:04.420
doesn't work normally. Insulin will bind to the receptor. It will activate the receptor. But the
00:28:10.240
next molecule, IRS1, PI3 kinase, all those molecules don't get activated. So glucose doesn't
00:28:16.180
get into the cell. That's diabetes. That same pathway activates nitric oxide synthase.
00:28:22.340
And that generates nitric oxide. Nitric oxide is the most potent vasodilator in the human body.
00:28:30.680
It's the most potent anti-arthrogenic molecule in the human body. So this defect that's in muscle,
00:28:37.940
and it's in cardiac muscle, and it's in skeletal muscle, this is all human data that I'm talking
00:28:42.920
about, not animal data. When you get a defect in that insulin signaling pathway, that's going to cause
00:28:49.080
diabetes. And it's going to promote cardiovascular disease. And that is why you can never separate
00:28:55.420
cardiovascular disease from diabetes. Now, as you pointed out, rightfully so, I believe that
00:29:02.820
high levels of insulin are also atherogenic. I don't want people saying Dr. DeFranco said you
00:29:09.360
shouldn't be giving insulin to people who need it. Of course, if people need insulin, you need to give
00:29:14.360
them insulin. But our beta cells make 35 units of insulin per day. So we showed this many years ago
00:29:21.000
when I actually was at Yale, that if you were to take a type 1 patient and they were lean, they would
00:29:27.480
only need 35 or 40 units of insulin to get their glucose controlled, assuming you gave the doses at
00:29:33.560
the right time. But we have a lot of people who are taking 100 units of insulin, both type 1s and type 2s.
00:29:39.220
So 3x physiologic. Yes. That kind of hyperinsulinemia, I think there's evidence to support
00:29:45.880
that's atherogenic. But now we have a problem. Can you have the glucose remain high? Yeah. It's a
00:29:50.820
question of, do you want to die quickly or slowly? But we have really good drugs. Yes, yes, yes. But
00:29:54.900
if you were only doing this with insulin, it's an awful trade-off. You're going to die very quickly
00:30:00.460
from hyperglycemia if you're left untreated. But if we overdo it with insulin to maintain normal
00:30:07.060
glycemia, we're going to kill you slowly. To quagma, you're stuck. Yeah. You have to treat,
00:30:11.100
but you also know that when you're giving these big doses of insulin, there may be some side effects.
00:30:16.580
This is something, Ralph, I don't think that has been necessarily appreciated by the medical
00:30:20.840
community. Absolutely not. There has generally been an ethos of, when I've talked to patients with
00:30:26.900
type 2 diabetes, what they've been told is, I'm told to cover with as much insulin as is necessary
00:30:33.160
to maintain my glucose levels in this range. And it means I can eat whatever I want. It's okay if I
00:30:40.940
have all the pasta and bread and sugar in the world, because as long as I'm covering it with insulin,
00:30:47.100
I'm okay. And then you find out, wow, you're taking 150 units of insulin a day in all of its forms,
00:30:53.680
the short acting, the long acting, et cetera. But I didn't actually realize that what we would
00:30:57.520
consider physiologic is 35. I may have known that at one point and I've since forgotten, but that's a
00:31:02.160
great reference. So basically, if there's a person with type 2 diabetes listening to us today
00:31:06.820
and they're taking 75 units of insulin, one of the takeaways should be, what do I need to do with
00:31:16.420
my nutrition and other pharmacologic activities, plus exercise, plus everything that's under my control
00:31:22.180
to maybe get that down to 35, where I would be at a physiologic level?
00:31:26.320
There are things as you already insinuated, weight loss, if you can get people to do it,
00:31:30.560
exercise. And then we can add medications in combination with insulin, insulin sensitizers or
00:31:36.720
some drugs to help you lose weight that will all also allow you to get that dose of insulin reduced.
00:31:44.140
The other thing we showed in this study, Dr. Del Prado, who's past president of the European
00:31:49.900
Diabetes Association, we took normal healthy lean kids, 18, 25 years of age. And we put them on the
00:31:57.460
clinical research center for three days and we gave them a very, very low dose of insulin infusion.
00:32:05.020
And we raised their fasting insulin from eight, which is what a normal person would be, to 20,
00:32:11.760
which is really quite low. And within 48 to 72 hours, they were as insulin resistant as a type 2
00:32:18.920
diabetic patient. So hyperinsulinemia induces insulin resistance.
00:32:26.760
So what insulin does is it down-regulates the insulin signaling transduction system.
00:32:32.500
So that insulin, when it binds to its receptor and then it activates IRS-1 and PI3 kinase and AKT,
00:32:38.960
that system is down-regulated by hyperinsulinemia. All of this that I'm telling you about,
00:32:44.020
it's all published. These are all studies done in humans. And this has also been shown in
00:32:48.660
rodent models as well. So this is another reason why we don't want people to be hyperinsulinemic.
00:32:55.220
You have to explain that to me again, Ralph. That is mind-boggling. I would never have predicted
00:32:59.120
that. So let me say it back to you because I feel like I missed it when I was writing something down.
00:33:03.700
You took normal volunteers who had a fasting insulin of eight.
00:33:10.100
Okay. And simply infused insulin in them, presumably with glucose.
00:33:15.580
Oh yes, of course. On the clinical research center, we can monitor and keep the glucose
00:33:19.240
perfectly constant. We're not letting the glucose change.
00:33:21.780
Person shows up, insulin eight, glucose is 90. You do a euglycemic clamp where you bring insulin up
00:33:28.560
only by one and a half per, one and a half X. Much less than would be when you eat a meal.
00:33:33.640
Exactly. Not even a postprandial bump, but now it's constitutively sitting there at 20.
00:33:39.420
And you've obviously had to bring glucose. You had to infuse glucose to maintain euglycemia.
00:33:46.400
48 to 72 hours. These people are as insulin resistant as type two diabetics.
00:33:51.160
Okay. Again, very, very counterintuitive because if our model is that insulin resistance,
00:33:59.940
which is the hallmark factor contributing to type two diabetes in the combination of
00:34:05.480
beta cell fatigue is driven by lipotoxicity, which we're going to come to.
00:34:11.800
Yes. These people didn't have any of that. These people didn't have any of the intramyocellular
00:34:17.300
lipid that we talked about with your colleague, Jerry Riven, as a predisposing factor.
00:34:23.080
It's the direct effect of insulin down-regulating the insulin signaling system and probably other
00:34:32.600
So then when you turn the clamps off, let's just say we ran this for 72 hours,
00:34:37.220
we've made them functionally diabetic. Turn the clamps off, how many hours or days?
00:34:45.020
I would predict probably within 24 to 48 hours, they would return to normal because we did this
00:34:50.820
acutely. Now, if we were able to do this for several months, then I would anticipate that the
00:34:58.640
insulin resistance would remain for a long period of time. And remember, when we treat type one
00:35:03.840
diabetics, we're always giving the insulin into the periphery. And you or I, when you ingest the meal,
00:35:10.620
where does the insulin go? It goes into the portal vein. So the liver is seeing a high level of
00:35:16.940
insulin. That's good. It says stop making glucose. But now it removes half of the insulin. So how much
00:35:24.160
insulin gets into the periphery? Half of what you secreted. Why? Because we don't want the insulin in
00:35:30.420
the periphery over insulinizing the periphery because it would make the muscle tissue very insulin
00:35:35.620
resistant. So the pancreas secreting insulin into the portal circulation. Liver sees the insulin.
00:35:41.700
Good. Stop making glucose. But it also takes up half of the insulin. So less insulin get enough to
00:35:47.720
nourish the muscle, enough to shut down the fat producing free fatty acids, but not enough to
00:35:53.480
hyperinsulinize the system. And in a certain way, if you're a diabetic and you are insulin resistant,
00:36:00.080
or an obese person, and you are insulin resistant, and you're hyper secreting insulin, it's kind of
00:36:06.180
working against you because it's a reverberating system that's making the insulin resistance
00:36:11.100
aggravated. So one of the big things that we've forgotten is that insulin, I told you, there are
00:36:17.360
two problems in diabetes. One is you don't make enough insulin. The other is you're insulin resistant.
00:36:21.960
You need to attack both problems. And the paper that I recently published, which is a perspective in
00:36:29.020
Lancet Diabetes Endocrinology, was to bring people back to, look, we're focusing on obesity and weight
00:36:35.780
loss, and we should, but we need to remember that we still have a genetic cause for the insulin
00:36:41.940
resistance. You go back to 1950, the incidence of diabetes was 2%. I've seen even data that says it
00:36:48.440
was 1% as recent as 1970. It's very low. Yeah. But these people were all lean and they're insulin
00:36:55.700
resistant. So there's a genetic cause of the insulin resistance. And you think, Ralph, that the greater
00:37:02.320
genetic effect is on the insulin resistance side or on the beta cell fatigue side? Both. Okay. So
00:37:08.600
let's tackle each. Since you started with insulin resistance, let's go there. Let's talk about what
00:37:13.280
we know about the genetics of insulin resistance. That's easy. Nothing. Truly nothing. I joke.
00:37:21.420
Well, let's say 20 years ago, we got involved in one of the biggest genetic studies called the
00:37:27.420
VEGAS study, Veterans Administration Genetic Epidemiologic Study. And we were convinced that
00:37:33.740
we were one of the people to do the first GWAS studies, that we would define all the genes that
00:37:37.920
are responsible. Well, we were not very successful. Even if you took the subset of people with type 2
00:37:44.680
diabetes who were lean and you compared them to people who were lean and non-diabetic versus obese
00:37:52.120
and diabetic, a GWAS was not able to identify a signal in those three cohorts? We identified several
00:37:59.300
and remember their associations. Of course. And they're in non-coding regions. The TCF7LT2 gene,
00:38:07.000
we found that, but that had already been described by Dr. Michael Stern in San Antonio many years before.
00:38:13.060
So we repeated what Michael showed. And other people have shown that. So there are a number
00:38:18.320
of associations. Again, if you ask me how many genes have we truly established that are really
00:38:26.060
important in terms of causing type 2 diabetes, I would say very, very few. I know the genetics
00:38:31.340
people out there probably hate this. And they'll say that we can put together a genetic score.
00:38:36.900
But when they talk about a genetic score, it's not that they've causably associated a gene with
00:38:42.760
diabetes. It's an association. It's an association. We have a whole different approach. If you want,
00:38:47.660
I can tell you what we're doing that may give some insight. And then people have started to think
00:38:52.700
about rare diseases. That maybe the problem is in one family, you have this particular genetic
00:38:58.980
mutation. Another family, you have a different genetic mutation. A third family, a different
00:39:03.860
genetic mutation. And then when you do the GWAS study, you got this mixture of individual genes.
00:39:10.320
What about the phenotype? That's the answer. I've taken care of a couple of patients with type 2
00:39:16.480
diabetes who are very lean, including one patient whose body fat by DEXA was about 8%. For people
00:39:26.740
listening, that is insanely lean. Very lean. So you take an individual whose body fat is 8%
00:39:33.440
and yet they have type 2 diabetes. The first thing that comes to my mind is a lipodystrophy.
00:39:40.180
Is this an individual whose adipose tissue is the problem? In other words, they're not able to
00:39:48.700
assimilate enough excess nutrient, i.e. glucose, into the fat cell. And so they're undergoing the toxicity
00:39:57.020
associated with an insufficient reservoir. Is that what could be the causal, not that I can tell you
00:40:04.120
what's causing the lipodystrophy, but is the lipodystrophy the issue that's driving the diabetes?
00:40:09.760
The answer to that is it's very clear that lipodystrophy can cause diabetes. This is, I would say,
00:40:16.260
a very, very rare and unusual cause, but well-established.
00:40:20.420
But you're saying that's not what would explain 1% of diabetics?
00:40:24.040
No, no. Jerry Shulman has done some beautiful work in this area. So it's unequivocal that
00:40:29.800
lipodystrophic people, because their fat cells can't take up the fat, it ends up in your myocardium,
00:40:38.120
Ends up in your beta cell in the muscle. But that's a very, very small percentage. So the basic
00:40:44.240
genetic etiology of the insulin resistance, the PPAR gamma gene has been associated. There are about
00:40:49.840
seven or eight genes. There's a recent study, I think it's in Nature Genetics by Brown,
00:40:56.000
where they've identified eight. And again, they're associations, except I would say the
00:41:00.600
PPAR gamma gene, that is pretty clear. That's a causal.
00:41:10.300
Yes. The number of genes that have been described. The other thing people said,
00:41:14.320
well, maybe there are 20 genes involved, each giving a small component. And that's why it's so
00:41:19.020
difficult. Well, all of these hypotheses have been difficult to prove. And the simple fact is,
00:41:25.220
we don't understand the genetic basis. In part, because diabetes, in my opinion,
00:41:30.740
is a very poor phenotype. Diabetes is a very heterogeneous disease. So when we talk about diabetes,
00:41:37.660
if that's your phenotype, it's not surprising to me that it's going to be difficult to define genes
00:41:44.980
that are related to diabetes. So what I'm going to tell you about, I don't want to take the credit
00:41:50.160
for this. So one of the people in my division, Dr. Luke Norton, working with Steve Parker at
00:41:55.800
Michigan, I'm involved because I'm doing the insulin clamp studies. We're taking as a phenotype,
00:42:02.520
muscle insulin resistance. This is a very, very specific phenotype. This is not diabetes.
00:42:09.820
The ominous octet, my pathophysiology. That's eight problems. Okay. This is muscle insulin
00:42:17.300
resistance. I'm going to do an insulin clamp now. And then I'm going to do a muscle biopsy
00:42:22.820
before I do the insulin clamp. And I'm going to do a muscle biopsy at the end of the insulin clamp.
00:42:29.200
And what happens? During the insulin clamp, I know exactly how sensitive or resistant you are to insulin.
00:42:35.620
I've got the most definitive phenotype in the world. No one get this kind of phenotype.
00:42:40.920
And now what do I see? An enormous amount of chromatin opens up. This is the epigenetic
00:42:46.620
component. Genes in a chromatin area that you're never, ever going to see in the basal state.
00:42:52.780
And that's why we think this is a hypothesis now that why it's been so difficult with all of these
00:42:59.340
GWAS studies to identify genes that are associated with diabetes. And now we're starting to see
00:43:05.500
diabetic people and non-diabetic people. We're starting to see some associations which we think
00:43:11.740
now are causal and we can relate to the insulin resistance with the clamp.
00:43:16.080
Let's just pause there for a second, Ralph. I want to make sure everybody's following what you're
00:43:19.400
saying. You're saying, look, one of the challenges of having a disease that isn't perfectly, perfectly,
00:43:25.200
clearly defined where every single member of the class that has the disease looks exactly the
00:43:31.260
same. The word for that is heterogeneous. So let's take an example where the disease is very
00:43:36.400
heterogeneous. Sickle cell anemia. Correct. Everybody who has sickle cell anemia from a
00:43:42.220
pathophysiology standpoint is identical. Correct. And guess what? There's a single mutation that
00:43:48.480
defines the disease. Because you have a single gene that defines the disease, one gene mutated produces
00:43:55.620
one change in one base pair that changes, one amino acid that changes the property of the hemoglobin
00:44:01.680
molecule, and everybody looks the same. But you're saying, Peter, it's totally different.
00:44:06.340
With type 2 diabetes, we have some people that are thin, some people that are fat, some people that
00:44:10.700
have lots of insulin resistance in the muscle, some people that don't seem to have much, but it's all
00:44:14.600
in the liver. I want to make sure we define the octet, the ominous octet. But if that's the case,
00:44:20.060
why would you ever expect to find a simple genetic answer? You got it.
00:44:23.400
Definition. Perfect. It's going to be a mess. Absolutely. And so if you don't have a very
00:44:28.100
definitive phenotype, it's going to be difficult. But the implication, by the way, is any physician
00:44:33.900
who approaches a patient with type 2 diabetes as a single entity is going to be providing suboptimal
00:44:39.620
care. Yes. I've been fighting for 20 years to convince people you need to start with combination
00:44:45.080
therapy from the beginning. Finally, 2022, the American Diabetes Association has made a comment.
00:44:52.340
And for the first time, suggest that you should consider starting with combination therapy. We
00:44:57.580
can talk about that. We're going to talk about the therapies in detail. But yes, you have to take a
00:45:01.400
precision medicine approach to type 2 diabetes, which begins by trying to identify which phenotype
00:45:06.600
your patient is. Before we clean it, I just want to make sure that everybody understands it's Luke
00:45:11.280
Norton and Steve Parker, and they're the brain child. I'm involved. I understand the disease. We're doing
00:45:17.280
the insulin clamps. We're giving them the phenotype, and they're doing single cell. It turns out there
00:45:22.340
are 10, 12 different types of cells within the muscle. So we tend to think the muscle, oh, there's
00:45:27.460
a myocyte. That's the problem. But it's probably cells also talking to each other, making it even
00:45:32.180
more complex. So we're at an early stage in the development, but we're enthusiastic. We really have
00:45:39.580
not discovered these genes. So we think that epigenetics are important, and this is part of the
00:45:44.660
epigenetic phenomenon. We'll see where it takes us, but we're pretty excited about these findings.
00:45:50.140
Let's go back to the ominous octet, make sure I have that defined and all our listeners do.
00:45:55.000
So in 2008 at the Banting Lecture at the American Diabetes Association, the title of the Banting Lecture
00:46:02.100
was From the Triumvirate to the Ominous Octet. So what was the triumvirate? I got the Young
00:46:08.140
Investigator Award, the Lilly Award from the ADA in 1987. So the triumvirate was very simple.
00:46:14.660
The beta cell, it fails. Insulin resistance in the muscle, when you ingested a meal, the
00:46:20.460
muscle didn't take up the glucose because you're insulin resistant, and insulin resistance
00:46:24.980
in the liver. When you ate a meal, insulin didn't shut down the liver. So that was the triumvirate.
00:46:31.280
So from the triumvirate to the ominous octet, we needed to add five more players. So who were
00:46:38.680
the new five players? So number four on the list was the fat cell and a very deserving
00:46:44.860
guy. So the fat cell is your friend initially. You overeat, you take in excess calories, you
00:46:51.920
store them in the fat cell that can't hurt you there. But if you keep expanding those fat
00:46:56.080
cells, the fat cells become very, very resistant to the antilipolytic effects of insulin. And
00:47:02.000
now you start to pour fat out into the bloodstream. We've shown this as a big interest to Jim.
00:47:09.480
Not that we should mire ourselves in teleologic things. Do you have a sense of why?
00:47:14.800
Yeah. So the insulin signaling system in multiple early steps become severely impaired. And when
00:47:20.900
you get insulin resistance in the glucose metabolic pathway, there are changes that alter the cell
00:47:25.900
metabolism. So you become very resistant to insulin's antilipolytic effect. And so now,
00:47:32.120
if you look at people who are obese or people who have type 2 diabetes, their plasma FFA levels are
00:47:37.920
very, very high. And those FFA levels, and this is lipotoxicity, and we've got a long history of
00:47:44.840
studying this, high FFA levels impair insulin secretion. High FFA levels cause insulin resistance
00:47:51.600
in the muscle. High FFA levels cause insulin resistance in the liver. High FFA levels impair
00:47:59.920
the insulin signaling transduction system. And in fact, one of my previous fellows who's now back
00:48:05.320
with me here at UT, Dr. Belfort, was the first author on this paper showing that just physiologic
00:48:11.500
rises in the plasma FFA literally obliterate the insulin signal transduction system, which is the first
00:48:18.140
step in glucose metabolism. I always thought that the reason we saw high free fatty acids in people
00:48:26.780
with type 2 diabetes was not because the fat cells were undergoing more lipolysis, but because the fat
00:48:35.040
cells were themselves becoming resistant to insulin and not able to take up fat. So same net effect,
00:48:44.360
but I was kind of drawing the arrow of causality in the other direction.
00:48:47.240
The arrow is more on the other side. The fat is pouring out fat. And you can show that the
00:48:52.420
lipolytic enzymes are all resistant to insulin. We've shown this. Other people have shown it.
00:48:57.100
So these elevated FFA levels are a disaster. So the fat cell initially is your friend.
00:49:03.540
Then it becomes a bad guy. So that's number four. Number five is the gastrointestinal trap.
00:49:09.560
And of course, we'll, I'm sure, talk more about this when we talk about treatment. But when you eat a meal,
00:49:13.980
you release two incretin hormones, GLP-1 and GIP, glucon-like peptide 1 and glucose-dependent
00:49:21.160
insulin trophic polypeptide. Those two incretin hormones, when you eat a meal, account for about
00:49:27.700
70% of the insulin that's released in response to the meal. So now, what is the problem? Is the problem
00:49:35.100
that you don't release enough GLP-1 and GIP? Or is it that your beta cell is refractory to the GLP-1
00:49:44.240
and GIP? Well, it's the later. Let's say that again, Ralph. I want to make sure people understand
00:49:48.140
this. And the reason it's important is, obviously, everybody listening to us right now is very
00:49:52.140
familiar with drugs like semaglutide and trzepatide. But I want people to understand why those drugs
00:49:58.620
were developed. And of course, semaglutide's already probably what the third generation of it anyway.
00:50:03.780
So when we go back in time, we'll understand why people try to develop these drugs. But just say
00:50:08.020
that again. So you eat your meal, GIP, GLP-1 are increased. And they come out normally.
00:50:13.820
Yep. That's not the problem. And they're telling the beta cell,
00:50:16.560
hey, make more insulin. Beta cell's deaf, not listening. It's resistant to the GLP-1 and GIP.
00:50:21.800
And he should be responding to 70% of his input should come from that signal.
00:50:27.140
70% of the insulin that's going to come out is dependent on that GLP-1 and GIP. So you can imagine
00:50:32.600
that that's a huge problem at the level of the beta cell in terms of the defect in insulin
00:50:37.320
secretion. And tell me, why is it mechanistically that the beta cell becomes deaf to GLP-1 and GIP?
00:50:47.880
So it's just another horrible piece of this puzzle where everything starts to work against
00:50:53.100
the patient. So this is an area, of course, intense investigation. But the clinical counterpart
00:50:58.000
of this, as you've already mentioned, the drugs that are out there, the GLP-1 receptor agonist,
00:51:03.020
what I'm doing is I'm giving you a pharmacologic dose of GLP-1. And I'm overcoming the resistance
00:51:08.940
at the level of the beta cell. Now, there's another component to this that we'll get to,
00:51:15.060
and that's glucotoxicity. And these were studies that were done by Jens Toltz and the group in Denmark.
00:51:20.680
They took people and they infused GIP. We're talking about GIP. And you don't respond to
00:51:27.200
the GIP. These are type 2 diabetics. And then they intensively treated them with insulin and
00:51:31.920
lowered their glucose. And then when they come back with the GIP, you release a normal amount
00:51:37.600
of insulin. So this is a glucotoxic effect. So you asked me mechanism. So we know that at least
00:51:45.160
for the GIP, the glucotoxicity is impairing the ability of the beta cell to respond to the GIP.
00:51:54.380
No, no. And that doesn't correct the GLP-1 problem. So there's true resistance still,
00:52:01.000
even though I normalize the glucose in terms of GLP-1. So this incretin axis, the gut,
00:52:07.420
is a very important endocrine organ. And that's number 5 in the ominous octet. Number 6 in the
00:52:14.220
ominous octet is the alpha cell. I would say the father of hyperglucagonemia, this is Dr. Roger
00:52:21.100
Unger in Dallas. He was one of the very first people to show that diabetics had very high glugon
00:52:27.020
levels. And glucagon drives- Tell people what glucagon does.
00:52:30.000
Yeah. Glugon, it drives hepatic glucose production. So if your glucose gets too low,
00:52:35.620
your alpha cells will release glucagon. So the alpha cell can sense the glucose. And so if you're
00:52:41.280
hypoglycemic, this is an important defense mechanism. You release glucagon, that stimulates
00:52:47.060
your liver and the glucose production goes up. It returns your glucose to normal. But a diabetic
00:52:52.940
already has a high glucose. We don't want high glugon levels. So paradoxically, there's very high
00:53:00.000
glugon levels in the diabetic. And those high glugon levels are very important contributor to the
00:53:07.380
hepatic insulin resistance because they're driving the liver to make glucose.
00:53:12.420
And sorry, just to make sure, I'm embarrassed to say I forget this from biochemistry. Is it driving
00:53:16.760
the liver to make glucose out of, for example, glycerol, amino acids, or other things?
00:53:21.140
Gluconeogenic pathway and glycogenolysis. Acutely, so if I acutely give you glucagon,
00:53:26.900
the first thing that happens, you break down glycogen. But very quickly, you get rid of all the glycogen
00:53:31.860
that's in the liver. And so chronically, now you're running on gluconeogenesis. But glugon
00:53:38.560
And does it also drive hepatic glucose output? Or does it just drive the creation of glucose?
00:53:45.160
It increases hepatic glucose output as well as gluconeogenesis.
00:53:48.420
Yes. And that's an important reason why you have fasting hyperglycemia. So when you wake up in
00:53:55.780
Yeah, and your blood sugar is 110 milligrams per deciliter.
00:53:58.020
That's the liver. And part of that is because your liver is intrinsically resistant to insulin.
00:54:03.140
Part of it is because the liver is now responding to the glucagon and producing an excess amount of
00:54:09.500
glucose, both through gluconeogenesis and through glycogenolysis. Although I would say the major
00:54:16.140
contributor is the gluconeogenic pathway. Now, that gluconeogenic pathway is also turned on because
00:54:22.980
fat is coming from the fat cell. Remember I told you the FFA is high.
00:54:29.660
We talked about some of the work that Jerry did. This is Jerry's work,
00:54:32.720
showing that glycerol coming from the fat cell is an important driver of gluconeogenesis.
00:54:38.000
And then hepatic fatty acyl-CoA levels are up because you have all this fat pouring in,
00:54:42.720
and that's activating the enzymes, pyruvate carboxylase, that are driving the gluconeogenic
00:54:48.160
pathway. So the metabolic, the actual pathways, I think, are very well worked out. So glugon,
00:54:55.720
And so is the alpha cell overproducing glucagon in this state?
00:54:59.440
Yes, absolutely. Absolutely. And this is really Roger Unger and Dallas's.
00:55:03.880
And again, why is it overproducing it? Why is it doing something that doesn't make any sense
00:55:10.520
In a certain way, this is also insulin resistance because hyperinsulinemia shuts down glucagon.
00:55:16.160
And we have very high fasting insulin levels in the diabetic. Okay. Now, what is it? What's the
00:55:22.640
sensing mechanism within? It's counterintuitive. Usually when things go wrong,
00:55:26.860
they get attenuated, right? Like it makes sense that the beta cell eventually fatigues because
00:55:32.260
that's an attenuation of doing something that it's getting tired of doing. The alpha cell
00:55:40.300
You're going to see it gets even worse when we talk about the kidney, which is number seven on the list.
00:55:46.180
Okay. So people don't know I'm also board certified in nephrology. In the old days,
00:55:50.940
I trained as a micropuncturist. I used to sit with a microscope. I would draw my little pipettes
00:55:57.600
out the night before and put the little micropipette in the tubules and I collect tubular fluid.
00:56:03.380
What I was interested in, and this is when I was a renal fellow at the University of Pennsylvania,
00:56:08.240
I was interested in glucose and phosphate transport. And I published a series of,
00:56:12.520
I'd say they're pretty elegant papers in the JCI looking at how glucose and what regulated glucose
00:56:18.980
in phosphate transport. And I knew that there was a molecule called fluorosin that blocked glucose
00:56:24.700
transport in the kidney. And so I took this molecule called fluorosin and it blocks glucose
00:56:30.860
transporters. There are two transporters in the kidney, SGLT2 and SGLT1. SGLT2 takes back 90%
00:56:38.660
of the glucose. If it does its job, SGLT1 takes back the other 10%. And then in your eye,
00:56:46.520
even though we filter 180 grams of glucose per day, no glucose appears in the urine. But what I showed
00:56:52.900
is that fluorosin, it blocked both SGLT2 and SGLT1. It blocked glucose transport and it also blocked
00:57:01.040
phosphate transport. And I showed that glucose and phosphate transport were coupled. When I was
00:57:07.080
doing these studies, even though I was a nephrology fellow, I had previously done my endocrine
00:57:12.940
fellowship at the NIH in Baltimore City Hospitals. I had an interest in diabetes and I said, this would
00:57:18.300
be a great way to treat diabetes. So in the old days, we did things for science and I published
00:57:25.300
a series of four papers in the JCI. And I never even thought of, to be honest with you, of patenting
00:57:32.440
this. I have a significant other who said to me one day, she said, Ralph, you're one of the smartest
00:57:37.440
guys I ever met. And I said, yeah, I know that. And she said, you're probably the stupidest guy I ever
00:57:42.100
met. And I said, why? She said, you could have patented this drug. So I actually worked with
00:57:49.040
Bristol-Myers Squibb and then AstraZeneca. And that eventually led to that glyphosin coming to the
00:57:55.400
market. But what we showed, and this is human biopsy.
00:58:06.600
Ampigliflozin, yeah. And then canagliflozin, ertogliflozin, we have a bunch of them.
00:58:10.540
They're all very good, basically do the same thing. But what we showed was the SGLT2 transporter
00:58:18.920
Let's just wrap our heads around that. Again, this is so counterintuitive.
00:58:23.480
Okay, this does not make any sense. I want to just bring it back to people
00:58:27.660
listening so they understand what we're talking about here. The kidney is this massive
00:58:31.560
filtration, another remarkable organ. No offense to the nephrologist, not as remarkable as the
00:58:36.260
liver, but every bit as remarkable in terms of-
00:58:39.360
I think it's more remarkable than the liver, guys. So that's okay.
00:58:43.120
Everything that's floating through our plasma, our kidneys, by the way, they take 25% of our
00:58:49.940
So it's massive. This organ weighs 2% of our weight and takes 25% of our cardiac output. Why?
00:58:56.320
Because we have to take everything that is in our circulation and dump it out. And then the kidney
00:59:02.400
has to selectively bring back in what's normal. This was explained to me, I still remember in medical
00:59:06.960
school, as a brilliant trick of evolution. Evolution was never going to be able to predict
00:59:13.120
every toxic thing we might encounter and therefore teaching the kidney how to spot toxic things and
00:59:19.440
get rid of them would have been a failed mission. Rather, it was better to teach the kidney what
00:59:24.780
was absolutely necessary and to discard all other things. So-
00:59:29.760
Yep. So it's the take everything out of your drawer and dump it out and only bring back the socks and
00:59:35.500
underwear that you need. So glucose, potassium, sodium, you name it, chloride, phosphate,
00:59:42.180
all of these things get dumped along with everything else. And then it knows I need this
00:59:47.040
much glucose. I need this much sodium. I need this much potassium. So SGLT2 does the lion's share of
00:59:53.780
It takes back 90% of the glucose. And now, so here's a diabetic with a very high glucose.
01:00:00.220
Right. So my point was SGLT2, if it had a brain, would say, oh, you have too much glucose.
01:00:07.380
Turn it off. How about we just stop reabsorbing all this glucose? But you said it's the opposite.
01:00:16.500
So as a doctor, I want the kidney to dump the glucose out in the urine.
01:00:20.840
But what is the kidney doing? It's doing the opposite. It's holding on to the glucose.
01:00:26.220
Even as a renal fellow, it became clear to me, this is such a simple way to treat diabetes.
01:00:32.460
And the fact is, it's so simple, no one thought about it. The only dumb thing that I did was I
01:00:36.780
didn't patent it, which I should have done. I'd probably never have to write another NIH grant for the
01:00:40.800
rest of my life. And then we went on to show, and in fact, this is the first definitive proof of the
01:00:46.940
glucotoxicity hypothesis. So we did all of these studies initially in animals, and this was all
01:00:53.860
published in the JCI. And Luciano Rossetti is one of the fellows at this time. Actually, Jerry Shulman
01:00:59.680
was a fellow on the papers as well. And what we showed was that you could take different types of
01:01:05.920
diabetic animal models, and you could show that they're reabsorbing excessive amounts of glucose.
01:01:11.760
And then if I treated them with fluorosin, because that's what was available, they simply
01:01:16.580
peed the glucose out in the urine. And now, all of a sudden, their beta cells started functioning
01:01:21.400
normally. Muscle insulin sensitivity improved. So, of course, that's wonderful if you're a mouse
01:01:27.340
or a rat. So we said, well, what about humans? And so the original studies actually were done.
01:01:33.560
There's kind of an interesting story behind this, but the initial studies were done with
01:01:38.480
dapogliflozin. And we showed with just 14 days of treatment with dapogliflozin, we markedly lowered
01:01:45.240
the fasting and postprandial glucose. We improved insulin sensitivity by 35%, and we made a major
01:01:52.240
improvement in beta cell function. Now, the beauty of this, SGLT2 inhibitors are only in the kidney.
01:01:59.540
They're not in your muscle. They're not in your beta cell. And the only thing that the SGLT2
01:02:04.720
inhibitors do makes you put glucose out in the urine. The only change in the plasma was the
01:02:09.680
glucose came down. And now insulin sensitivity improved, and muscle and beta cell function
01:02:14.640
improved. And this was the first, now in humans, even though the original studies were done in
01:02:19.560
animals, first studies to show an improvement in the reality of glucotoxicity. What was interesting
01:02:27.000
is that when we started to work on developing this with BMS and AstraZeneca, the company decided,
01:02:33.500
well, we should get some nephrologists in to see about this story. They said, look, if you listen
01:02:38.860
to what Dr. DeFranzo says, this will be a disaster. And they said, why? Because if you put glucose in the
01:02:44.440
urine, it will glycosylate the proteins, then you'll cause kidney damage. And they actually held up the
01:02:51.560
development of the SGLT2 inhibitors. And the way we finally convinced them to go ahead was that
01:02:57.500
there's a disease called familial renal glucosuria. From day one of their life, they're bringing out
01:03:02.880
tremendous amounts of glucose. They have perfectly normal kidney function.
01:03:06.640
How many grams of glucose can be differentially or extra secreted, basically, in the presence of an
01:03:14.000
SGLT2 inhibitor today? It kind of depends on what the level of your GFR is. But it could be anywhere
01:03:19.620
from 40 to 60 grams up to 120 grams of glucose. And the higher would be in somebody with a higher
01:03:25.980
gradient? Yeah, the higher the glucose. The higher the, yeah. Yes, because you filter more glucose,
01:03:30.580
then there's more glucose to be blocked at the level of the kidney. And these drugs are very,
01:03:36.260
very good. Now, I actually, in developing these drugs, as I said, I'm also a nephrologist.
01:03:42.640
Based on the Barry Brenner hypothesis, I predicted these drugs would save your kidneys,
01:03:48.100
according to the Brenner hypothesis. And that's all turned out to be correct. These drugs are
01:03:52.720
great for the kidney. What I never, ever envisioned is that these drugs were going to save your heart.
01:03:57.740
Good for the heart, yeah. I want to come back to that because I'm making notes of other things I
01:04:01.280
want to come back to. And so I want to come back to, just so you can hear me say it now and we
01:04:05.900
remember, I want to come back to combined inhibitors, the SGLT2, SGLT1 inhibitor. I think it was a new
01:04:11.880
drug. Sodoglyphlosia. Yeah, it does both. We'll just touch on that. And then I want to also come
01:04:15.500
back to the broader gyroprotective nature of the SGLT2s as documented by the ITP in mice and then also
01:04:23.020
in the human studies for cardioprotection. But before we do that- We need to finish the
01:04:26.400
homoshock day. Exactly. Let's go back to number eight.
01:04:28.580
The brain. So the brain plays a role in a somewhat indirect way. So every day you have your breakfast,
01:04:36.340
your lunch. I actually eat only once a day, but at some point you eat a meal. And at some time during the
01:04:41.240
meal, you'll say, okay, I'm hungry. I stopped eating. Why'd you ever think? Why does that happen?
01:04:46.140
Well, because there are certain hormones that are released or inhibited that tell you, okay,
01:04:50.420
you're satiated. Stop eating. Well, one of the very important ones is GLP1. That same thing that's
01:04:55.820
increasing insulin secretion. Your brain has become very resistant to GLP1. When you eat a meal,
01:05:02.000
amylin comes out. It comes out in a one-to-one ratio with insulin. Your brain has become
01:05:06.060
resistant to amylin. Your brain is resistant to leptin. So there are a lot of these interrectic
01:05:11.780
molecules that your brain has become resistant to. And these molecules, it's another area of
01:05:19.760
interest of mine. These, they work in the hedonic areas in the brain. So in the putamen,
01:05:25.280
the prefrontal cortex, and they tell you to stop eating. And unfortunately, and this is the big
01:05:31.460
unknown is what's going on in the brain. The neurocircuitry is clearly distorted. Not only
01:05:36.960
is the neurocircuitry distorted, one of the big things that we are interested in, Dr. Peter Fox and
01:05:42.520
myself at UT, is if you look at the gray matter in these areas, in the areas that are critically
01:05:48.680
important in regulating your appetite, there's shrinkage of the gray matter area, okay? And in
01:05:54.320
these areas, if you do an insulin clamp, the brain is insensitive to insulin in your eye. In obese
01:06:00.740
people, these areas in the brain where there's abnormal, marked increase in glucose uptake.
01:06:07.160
Incredible finding. Who would have thought? I'm sorry. You're saying that these are the few areas
01:06:12.860
in my brain and your brain that are actually default insulin insensitive. Yes. Don't take up glucose.
01:06:19.620
Correct. If I do an insulin clamp. So what is their fuel source? Lactate? Well,
01:06:24.380
in response to insulin, they don't take up more glucose. Oh, okay. I'm sorry. Got it.
01:06:28.280
Because remember, this is from the Cahill studies. As long as your glucose is about 50,
01:06:32.900
your brain is happy. So this is actually in the evolution of the human being, this is phenomenal.
01:06:38.720
Because in the old days, you may not eat. You may slaughter one of these beasts.
01:06:43.360
Yeah. You're not eating for days. You're not eating for days. So your glucose would drop. So if your
01:06:47.320
normal fasting was 80, if it dropped to 40, you're okay because your brain saturated at 40. If you got
01:06:53.100
below 40, you're in trouble. So you have a big buffer here. But now if I infuse insulin and your
01:06:58.980
glucose is 80, your brain doesn't take up more glucose. It's, quote, insulin insensitive in a
01:07:03.820
certain way. Now, of course, if you take people with mild cognitive impairment, there've been some
01:07:09.400
experiments that actually suggest in these people, insulin infusion can transiently improve glucose
01:07:14.500
uptake. But presumably, that's because they're insufficiently getting glucose in the disease state.
01:07:19.500
Yes. This has been postulated. This also suggests that there's brain insulin resistance,
01:07:25.560
which is, I'd say, an interesting concept and may play some role in this neurocognitive
01:07:30.720
dysfunction, Alzheimer's, whole different story that's in evolution. But to come back to the
01:07:36.160
ominous octet now, if you overeat, what happens? You gain weight. And when you gain weight, you become
01:07:41.660
insulin resistant, severely insulin resistant. That's lipotoxicity. And we've done studies in
01:07:48.440
both directions. I can put an IV and I can infuse an emulsion of free fatty acids. And I can show
01:07:56.420
within two to four hours, I induced severe insulin resistance in the muscle, in the liver, and I
01:08:03.360
markedly impaired beta cell function. And then we don't have this drug in the United States, but there's
01:08:09.500
a drug that's available in Europe, and I have an IND to use it. It's called the Cipamox. It inhibits
01:08:14.760
lipolysis. It's like SGLT2 inhibitor. The only thing to do is block glucose reabsorption in the
01:08:20.720
kidney. A Cipamox, all it does is do block lipolysis. It lowers your FFA level. And we've done this.
01:08:27.400
Does it result in any meaningful clinical increase in adiposity, or is it so subtle that you don't
01:08:32.780
notice it? Over 12 days, no change in adiposity, huge improvement in insulin sensitivity and muscle.
01:08:40.760
I don't know the company that developed it in Europe ever tried to get it approved in the U.S.
01:08:46.480
It's, I would say, modestly effective in lowering triglycerides. And we have phenofibrates,
01:08:53.440
which are much more effective. So that may be the reason...
01:08:56.840
But the triglyceride and the FFA are not the same thing.
01:08:59.100
No. But that's the reason why it's approved in Europe. But if you lower the FFA, that's the
01:09:05.480
precursor for triglyceride synthesis. So it has an effect to lower the triglycerides.
01:09:10.760
But the key thing is if you lower the FFA, and we did this for 12 days, we did it in both
01:09:15.700
obese people and in diabetic. You markedly improve insulin sensitivity in the muscle. If using
01:09:22.040
MRI, you can measure muscle fat. It goes down dramatically and correlates with the improvement
01:09:26.980
in insulin sensitivity. We also measured ATP generation because there's this issue is...
01:09:33.500
There's clearly mitochondrial dysfunction if you're a diabetic. That's unequivocal.
01:09:37.320
The controversy is, is the mitochondrial dysfunction causing the insulin resistance or is the insulin
01:09:44.940
resistance causing the mitochondrial dysfunction? So in this study that we did, when we lowered the
01:09:51.680
FFA and lowered the muscle lipid content, we saw about a 50% improvement in ATP generation,
01:09:59.720
mitochondrial ATP generation. So at least this says that part of the mitochondrial dysfunction
01:10:05.700
is secondary to the lipotoxicity and insulin resistance. But this still remains, I would
01:10:12.200
say, a controversial topic. Clearly there's mitochondrial dysfunction. If you can improve
01:10:17.840
it, that's going to improve insulin sensitivity.
01:10:20.420
Is there anything that improves mitochondrial function more than aerobic exercise training?
01:10:25.240
P-oglitazone. The drug that I can't get people to use, which is a phenomenon. By activating PPAR
01:10:32.620
gamma, it does a lot of good things. And one of the important things that it does, it has a huge
01:10:38.100
effect to improve mitochondrial dysfunction. And it has direct effects. It works directly through
01:10:44.060
PPAR gamma to do this. And it also binds directly to the mitochondrial pyruvate carrier. And that influences
01:10:51.500
flux through the mitochondrial chain. Why don't people use this drug today?
01:10:57.680
Huge misconceptions. I guess we'll talk about therapy.
01:11:02.660
As part of my triple therapy regimen, I use a GLP-1 receptor agonist. I use P-oglitazone.
01:11:09.960
And I use an SGLT2 inhibitor. There's a fourth good drug, and that's metformin. And you might ask,
01:11:16.560
well, why is metformin number four on my list of good drugs since I single-handedly brought metformin
01:11:22.120
to the United States in 1995? No other endocrinologist involved in this. 1995, metformin was a
01:11:30.060
revolutionary drug. Why? We had insulin and sulfonylureas. So now we had a drug that really could work.
01:11:36.600
It's still a very good drug. And of course, it's very cheap. It's $5 a month in the state of Texas.
01:11:41.860
But we have much better drugs. P-oglitazone causes weight gain. Now, here's the problem.
01:11:47.560
It'll become very obvious. We talk about these paradoxes. The more weight gain, the greater the
01:11:53.420
drop in A1C. The more weight gain, the greater the improvement in insulin sensitivity.
01:12:00.200
No. I'll come back to that in a second. It is fat weight gain, and I also believe muscle weight gain.
01:12:05.700
The more weight gain, the greater the improvement in beta cell function. The more weight gain,
01:12:09.420
the greater the drop in blood pressure. The more weight you gain, the greater the drop in
01:12:13.520
triglycerides. The more weight you gain, the greater the rise in HDL cholesterol. Sounds like
01:12:19.160
terrible drug. So here's another one of those paradoxes. Why? We know if you overeat and gain
01:12:24.680
weight, that's a disaster. But with P-oglitazone, the more weight you gain, everything gets better.
01:12:29.760
What P-oglitazone does is it shifts weight around in the body. In my opinion, it's the best drug for
01:12:35.740
treating NASH. No drug is going to beat P-oglitazone. The pharmaceutical companies,
01:12:40.200
if you had to go up against P-oglitazone, all these NASH drugs, I don't believe you can beat
01:12:47.040
Actos. As I said, there's this paradox. So why do you gain weight? P-oglitazone,
01:12:53.400
it redistributes fat in the body. It gets it out of the muscle, puts it in subcutaneous tissue.
01:12:58.440
Gets it out of the liver, puts it in subcutaneous tissue. Gets it out of your beta cells,
01:13:02.340
put it in subcutaneous tissue. That's not going to make you gain weight. The richest density of
01:13:07.340
P-par gamma receptors in the hypothalamus. So when I activate these P-par gamma receptors in the
01:13:12.780
hypothalamus, you eat, okay? It makes you hungry. That's got nothing to do with redistributing the
01:13:18.900
fat in the body, except they parallel each other in association. And so you see the weight gain and
01:13:25.980
people say, oh, that's bad. But what's really doing the thing is this recycling and moving the fat around.
01:13:32.340
The other negative thing about P-oglitazone is it causes fluid retention. So people have
01:13:38.080
associated fluid retention with heart failure. Now, why do you get fluid retention? Again,
01:13:43.860
people do not understand. P-oglitazone, the only thing, the only drug that is a true insulin
01:13:51.240
sensitizer is P-oglitazone. Metformin is not a true insulin sensitizer. That's a total misconception.
01:13:55.860
P-oglitazone, that insulin signaling defect that I told you about, P-oglitazone corrects that defect.
01:14:04.540
We kind of glossed over this. We're going to spare people the details, but it's probably worth just
01:14:08.660
reminding people. Insulin binds to the insulin receptor. That's outside the cell. That's a
01:14:15.780
There are three tyrosine molecules, and they have to be phosphorylated. These are studies done,
01:14:20.920
Ron Kahn and other people in Boston. You mutate one of those tyrosines, you become a little insulin
01:14:25.640
resistant. You mutate two of them, you become moderately insulin resistant. You mutate three
01:14:30.440
of them, you're severely insulin resistant. Insulin binds to the receptor. Okay, that happens normally
01:14:35.840
in diabetics. We showed there's no problem there. Then IRS-1, insulin receptor substrate-1.
01:14:44.520
Yes. It interacts with the insulin receptor, and it gets phosphorylated on the same three
01:14:50.220
tyrosine molecules. Then you activate PI3 kinase, AKT. We could add some more molecules in here,
01:14:57.680
but this is the insulin signaling pathway. That's the pathway that the earliest defect that you can
01:15:05.340
And if I recall, isn't this where Jerry argued that the intramyacellular lipid was creating the
01:15:14.700
defect in that pathway? The accumulation of intramyacellular lipid?
01:15:18.260
So what Jerry has shown very elegantly is that there are certain lipids, DGAT, and it's a specific
01:15:24.520
DGAT. There are like several types of DGAT molecules, which has confused things. So he's shown
01:15:30.420
there's a specific one of the DGATs that activates these atypical PKC molecules, and that serine
01:15:36.940
phosphorylates the insulin receptor. When you serine phosphorylate the molecules in that pathway,
01:15:42.880
it inactivates them, okay? And so he's done these very nice elegant studies, both in peripheral muscle
01:15:48.320
and in the liver, showing that this plays a very, very important role in the insulin resistance.
01:15:53.760
This is part of the lipotoxicity. I don't believe that this is the genetic basis, the genetic
01:15:59.780
etiology. You get fat and you start putting fat everywhere. This is very important, critically
01:16:04.480
important. That was when he gave his Banting lecture, and I might say I am delighted that I
01:16:09.800
got to write his letter of nomination for the Banting lecture. He was incredibly deserving. He's
01:16:14.900
done phenomenal work in this area. But that was his Banting lecture, and you're right. Very,
01:16:20.100
very, very, very important mechanism of insulin resistance.
01:16:24.720
And so given that that's both a very important and very common pathway towards insulin resistance,
01:16:31.120
bringing it back to PPAR gamma, PPAR gamma is part of the pathway. It's part of the IRS-1,
01:16:38.180
PPAR gamma, PI3K, GLUT4, bring the glucose in the cell. In other words, if people don't want to get
01:16:45.520
mired down in this, which is totally understandable, insulin hits a receptor. That receptor kicks off a
01:16:51.260
cascade that ultimately results in a little tube, like a little straw that goes into the cell surface
01:16:57.040
that allows glucose to freely flow in, in its gradient. Remember, that same pathway also activates
01:17:03.820
nitric oxide synthase. That's right. Generates nitric oxide. And that's why we see in patients with
01:17:09.080
insulin resistance, even if glucose is controlled, cardiovascular disease is still up.
01:17:20.080
So what does it do? It activates that signaling pathway. You generate nitric oxide. Now you vasodilate.
01:17:27.980
That's why the blood pressure drops. When you vasodilate, so I'm a nephrologist. I understand this
01:17:32.980
very clearly. Anytime you end up refuse the kidney, you hold on to salt and water. You become an edematous.
01:17:39.940
And so people associate fluid retention and edema with heart failure. So we did the definitive
01:17:46.920
studies published in Diabetes Care in 2017. People just don't read. So we took people who had diabetes
01:17:53.560
and we treated them with pioglitazone. And then using NMR, very, very sophisticated techniques,
01:17:59.820
what we showed is pioglitazone markedly improved myocardial blood flow. Now, these numbers are
01:18:06.220
going to blow your mind away. Myocardial insulin sensitivity with PET and fluorodeoxyglucose
01:18:11.960
improved by 75%. Your heart, we showed this before, is severely insulin resistant. I came pretty damn
01:18:19.980
close to normalize insulin sensitivity in your heart. Now, since we're doing the insulin clamp with
01:18:26.180
74% improvement in skeletal muscle insulin sensitivity.
01:18:30.120
Exactly the same. If you look at ejection fraction, it went up by 5% to 10%. Not down. It went up.
01:18:38.320
If you look at every measure of diastolic dysfunction, E over A, E over E prime, LV,
01:18:45.260
peak filling pressures, etc. Cardiology people understand this. The point is, whether you're
01:18:49.880
looking at systolic function or diastolic function, it all got better.
01:18:53.760
It's a victim of maybe not so nuanced thinking about the drug. Now, the critic would push back
01:19:00.520
and say, okay, Ralph, but don't we have better drugs? Like, I mean...
01:19:03.640
No drug that corrects insulin resistance. Metformin is not an insulin sensitizer. And people keep going
01:19:09.080
back to this. I brought metformin to the U.S. in 1995. I know this. I did all the mechanism of
01:19:15.060
action studies. What we showed was the insulin clamp. The drug absolutely does not improve insulin
01:19:21.060
sensitivity. So let's talk about metformin. Everybody wants to know if metformin is
01:19:24.600
gyroprotective. But let's just remind people, metformin inhibits complex one of the electron
01:19:31.440
Yes. I'd say this is still controversial. In high doses, for sure, yes. And the kind of doses you see
01:19:38.300
with giving metformin, I would say somewhat equivocal.
01:19:41.940
Is the belief that metformin's efficacy in diabetes is through reducing hepatic glucose output?
01:19:50.320
Okay. And what's the mechanism by which it reduces hepatic glucose output?
01:19:53.520
Inhibiting the mitochondrial chain and inhibiting gluconeogenesis. Well, for sure,
01:19:58.100
it inhibits gluconeogenesis. Metformin gets into cells through the organic cation transporter.
01:20:04.300
The organic cation ion transporter doesn't exist in muscle. It can't possibly be an insulin
01:20:10.260
sensitizer in muscle. You're asking the drug to do something that's impossible.
01:20:18.100
Why does lactate go up when people are taking metformin?
01:20:21.460
Level of the liver. It's interfering with aerobic metabolism. There's a block.
01:20:26.900
This is very important. I have erroneously always believed, so I'm really happy to be corrected.
01:20:32.480
I love being proved wrong. I have always believed that the reason we saw an increase in fasting
01:20:40.040
lactate, even in healthy people, if they took metformin was because of the inhibition of the
01:20:49.960
And you're saying, Peter, that's not possible. It can't get into skeletal muscle?
01:20:54.180
Absolutely not. A single molecule in the world of metformin has ever gotten into
01:21:03.080
The organic cation transporter. That's the transporter by which metformin enters cells.
01:21:09.840
It does not exist in skeletal muscle. It does not exist in cardiac muscle. So metformin cannot
01:21:16.420
get into these tissues. It's a huge, major misconception. It can, if you have very, very
01:21:24.100
high doses that can occur when you have very low GFR because metformin is excreted by the kidney,
01:21:29.980
if the metformin levels build up, you can get lactic acid doses. That's a very, very rare
01:21:35.060
complication. There's not a reason why you shouldn't be using the metformin. And I'm not
01:21:39.920
saying that metformin is not a good drug. It is a good drug. I don't think it's as good as the
01:21:44.380
other three drugs we talked about, but yes, it does at high doses increase the lactate level,
01:21:50.740
all in effect on the liver. And the old drug that caused all the problem was fenformin by guanide as
01:21:57.280
well, but it had a powerful effect. Yeah. Fenformin was much more powerful.
01:22:00.880
Yes. And when you say high dose, I mean, is two grams a day of metformin?
01:22:07.300
Okay. So metformin has the following going for it. It's free.
01:22:15.000
And it does a pretty good job at reducing hepatic glucose output.
01:22:19.480
Yeah. And it has no myotoxicity, frankly, any toxicity.
01:22:24.600
Yeah. The GI, but you can usually overcome that with a slow ramp up.
01:22:27.880
Yeah. See, this is the reason why some people thought it's an insulin sensitizer.
01:22:31.900
15 to 20% of people have significant GI side effects and they lose weight. And if you look
01:22:37.620
at the studies on average, there's about a three kilogram weight loss with metformin. And when you
01:22:44.040
lose weight, you can improve insulin sensitivity. So I think this is what's confused some of the old
01:22:49.960
literature to make people think that metformin was an insulin sensitizer. But when we developed
01:22:55.000
metformin and I did all of the work that went to the FDA, if you look at the New England Journal
01:23:00.580
of Medicine, article 1995, there are only two names on the paper, myself and a PhD oncology lady who was
01:23:09.700
the person from Leapha Pharmaceuticals. We did insulin clamps, many of them. We never could
01:23:15.580
show metformin to improve insulin sensitivity using the gold standard with radioisotopes.
01:23:20.780
Do you think many people, I feel like I'm asking you this question a lot and it's getting a little
01:23:24.940
old, but do you get the sense that most people are still thinking what I think?
01:23:33.740
And it's an insulin sensitizer by getting into the muscle and inhibiting complex one.
01:23:37.300
Absolutely. People have done PET studies. So you can label metformin and you give it. And then
01:23:42.660
where do you see? It's all accumulating in the liver in the first three, four, five,
01:23:47.540
10 minutes. And then what happens? You start to see it accumulating in the kidney. Why? Because
01:23:52.580
that's where it's excreted. And then wait another five or 10 minutes, you see the bladder. And that's
01:23:57.280
the only place where you see metformin. You never see it in the muscle. And that's even more
01:24:02.480
graphic demonstration that metformin is not getting into muscle. And it is definitely not
01:24:08.720
Is there a downside to using metformin in combination with the other three drugs?
01:24:13.600
No. The classic study, which we'll talk about, which to me should change the entire approach to
01:24:18.800
treating diabetes, it's called the EDICS study. And in the EDICS study, what we did is we used triple
01:24:26.060
therapy right from the beginning. And my point of the Banting lecture, the ominous octet, if you have
01:24:32.520
eight problems, there I'm sure are going to be more to be found than I can give you a few more if you
01:24:36.940
want. But if you have eight problems, why in the world do you think one drug is going to correct
01:24:41.180
eight problems? It ain't going to happen in our lifetime. So the point was you need to use drugs in
01:24:46.560
combination. We said we're going to use what we think are the best drugs at the time. So we started
01:24:51.920
with metformin with exenotide, an old time GLP-1. This is not the kingpin.
01:25:00.080
Yeah, exactly. Because that's what was available.
01:25:03.960
No, it's a good drug. Sure, it's not semaglutide or trezepatide, but you have to start somewhere,
01:25:09.460
Yeah. Let's pay it its dues as being the Gen 1 OG version of that drug, without which we might not
01:25:14.400
have, we wouldn't have semaglutide or trezepatide.
01:25:17.120
Yes. It's kind of an old timer. In pioglitazone, that was the triple therapy.
01:25:21.080
And then we said, every diabetic patient, there are 315 people in this study. They're having insulin
01:25:27.320
clamps, hyperglycemic clamps, muscle biopsies. No one in the world can do this study. 315 people,
01:25:32.320
followed for six years. So we said, this is what we believe is the appropriate therapy.
01:25:38.180
Then we said, we'll use the ADA approach. The ADA approach is you start on metformin. And when you
01:25:43.660
fail, even not explicitly said, the next drug that's used is sulfonylureas. And then the third drug
01:25:50.500
that's added is insulin. And we said that the goal of therapy was an A1C of six and a half. Okay. And
01:25:58.920
that if your A1C rose above six and a half, either on R triple therapy or on the stepwise treat to fail
01:26:07.740
approach that the ADA says. ADA says, start metformin. You fail. You add sulfonylurea. You
01:26:13.160
fail. You add insulin. You titrate the insulin, basal insulin up to 60 units. And we said, 60 units is
01:26:19.880
really where we'll cap it. Yeah. You're already at 2x physiologic. Yeah. Now you have to split the
01:26:25.220
dose of insulin. You have to be adding rapid acting insulin. I think this is quite reasonable. Six years
01:26:30.840
later, 29% of the people with the ADA approach have failed. Their A1C is above six and a half. Six years
01:26:39.480
later with our approach, 70% of the people have an A1C. It's less than six and a half. Why? Insulin clamp.
01:26:47.920
Huge improvement with our therapy. Okay. This is the EDEK study. The three-year data published, the six-year
01:26:53.280
data we're writing it up. How much improvement in insulin sensitivity with the ADA approach? Zero.
01:26:57.940
Beta cell function. You have almost a normal beta cell. Ralph, why the disconnect between what you're
01:27:03.580
seeing in the EDEK study and what the ADA is promoting? You have to ask the ADA. What's their
01:27:09.200
answer? If I'm a patient or if I'm a physician who's treating these patients and I'm saying, guys,
01:27:14.360
I'm confused. I'm looking at the literature. I'm seeing this. I'm looking at your... And by the way,
01:27:18.040
I see this with the AHA and cardiovascular guidance, so I'm not singling out you. But is this simply a
01:27:23.820
question of the pace at which medicine moves is so glacial? That's part of it. Plus, remember,
01:27:29.680
if to do 315 people, follow them for 16 years and do all the stuff we did, it's unequivocal.
01:27:37.160
And why has there not been political pressure? Because the cost of insulin is enormous.
01:27:44.280
They finally said in 2022, there's a state, the ADA approach is not based on pathophysiology.
01:27:50.260
I view myself as a scientist as well as a clinician. As a good clinician, I've taken care
01:27:56.080
of hundreds of thousands of patients and at 850 publications. I do clinical research. I work in
01:28:02.160
people. When I do an insulin clamp study and I see an improvement in insulin sensitivity,
01:28:07.480
I do a hyperglycemic clamp and I see in 315 people your base self-function. I don't need 5,000 people.
01:28:14.040
I can't do this study in 5,000 people. No one can do this study. But the tools that we're
01:28:19.900
using are so powerful. Look, if I normalize your insulin sensitivity and I give you a normal beta
01:28:25.040
cell and your A1C is less than 6 and a half, well, it's half of the 315 people. Why do you not think
01:28:31.280
that's the best therapy? And now on the other side, I have this metformin SU insulin and 71%
01:28:38.320
of the people have failed. There's zero improvement in insulin sensitivity, zero improvement in beta
01:28:42.900
cell function. Why do you think that's such a good regimen? Now, above and beyond all that,
01:28:47.720
I didn't do this study. This is the GRADE study, G-R-A-D-E. It's sponsored by the National
01:28:54.420
Institutes of Health. And what the GRADE study said, and I have to say this is the third study
01:28:59.660
that's shown what I'm going to tell you. Dr. Robert Turner's United Kingdom Prospective Diabetes
01:29:04.340
Study showed this in 1990. Stephen Cairn showed this in the ADOPT study in year 2005. And now we have
01:29:12.440
the GRADE study, 2020. I call this the 15-year revelation. We saw what didn't work, 1990. Oh,
01:29:19.480
Stephen Cairn did it again. Oh, it didn't work in 2005. And now 2020, NIH did it. You know what?
01:29:26.620
I'll show the same thing. And this was a sequential approach.
01:29:30.040
You had to have failed on metformin to get into the study.
01:29:32.980
Okay. So you failed in metformin, then you enter the study, then we go single agent.
01:29:36.680
They want to know what's the best next drug to add to metformin. I can add a sulfonylurea. A1C went
01:29:42.860
down in year one, up straight. Tell folks how a sulfonylurea works.
01:29:47.820
Sulfonylureas are old-time drugs. They bind to the sulfonylurea receptor on the beta cell and they
01:29:52.880
kick out insulin. And they're very good drugs in the first year. And then they burn out the pancreas.
01:29:57.640
Well, they stop working. Yeah. I mean, basically,
01:30:00.180
they kick the can down the road without addressing the pathophysiology.
01:30:08.060
Yep. So a DPP-4 inhibitor increases your GLP-1 and your GIP level endogenously. It makes your
01:30:15.660
gastrointestinal cells, the K and the L cells that secrete the GLP-1 and GIP, makes them make more
01:30:21.820
GLP-1 and GIP. But it doesn't increase the GLP-1 and GIP enough to really give you a knockout punch.
01:30:27.900
I give you an injection, you all, people are out there, Monjaro or Semaglutide,
01:30:33.220
that's the knockout punch. When I give you the DPP-4 inhibitors, they do increase GLP-1 and GIP a
01:30:39.380
little bit, but not powerful enough to give you a long-lasting effect. So first year, A1C comes down,
01:30:45.320
A1C goes up. Third drug, this was very surprising to me. This was Liraglutide. This is one of the
01:30:52.040
earlier GLP-1 receptor agonists. I thought that was going to work the best. It failed. It worked
01:30:58.040
in the first year and then failed. And then the fourth drug was insulin. And the docs just didn't
01:31:04.100
titrate the insulin enough. So A1C down and then they failed. So five years later, all four of those
01:31:10.580
regimens added to metformin failed. Triple therapy, Exendatide, an old-time GLP-1,
01:31:16.940
P-oglitazone, which people don't appreciate, the only true insulin sensitizer, and metformin,
01:31:22.220
six years later, 70% of the people have an A1C less than seven.
01:31:27.560
And let's just go back. Metformin is free. The Gen 1...
01:31:35.780
Okay. So we have three free drugs that work better.
01:31:39.160
Now it's interesting, when you talk about today's triple therapy, which is way more efficacious,
01:31:46.260
The SGLT2 inhibitors are very expensive. In the modern day, Gen 3, Gen 4, and soon we'll
01:31:54.580
$1,000 a month. Now, are they great drugs? Of course.
01:31:58.480
I guess the question is, do you need to be on those drugs if your old version of triple
01:32:05.660
Our old version is incredibly effective. The problem is you can't get people to use P-oglitazone.
01:32:11.440
And the reason is patients are frustrated with the fact that they're retaining water?
01:32:16.760
How much weight do they gain, typically? How many kilos?
01:32:18.700
Depends on the dose. I don't go to the 45 milligram dose. So at the end of the year,
01:32:23.780
they may gain two or two and a half kilos at the 15 and 30 milligram dose. Okay? But their A1C
01:32:29.880
If you give PO plus a modern day GLP-1, don't you offset the weight gain?
01:32:38.200
Oh, you lose all the weight you lose with the GLP-1 receptor.
01:32:41.320
So if a patient is willing to go down the path of a modern day GLP-1...
01:32:47.920
Absolutely. And it also gets rid of the edema. And believe me, their A1Cs are down in the
01:32:53.100
normal range. Let me tell you this first thing about P-oglitazone and the proactive. I'll
01:32:57.480
come back. So in the proactive study, this was done a long time ago. You have to show cardiovascular
01:33:02.580
safety. 5,238 people to get into the study, you had to have an MI stroke or something bad.
01:33:08.880
Half people on P-oglitazone, half the people on placebo. Okay? And the MACE endpoint, major adverse
01:33:14.840
cardiovascular events, which is non-fatal MI, non-fatal stroke, cardiovascular mortality,
01:33:20.320
you have to show the benefit to get approval by the FDA. The MACE endpoint was positive. And so
01:33:25.400
when I talk to cardiologists, I like to say, what was the one thing in the P-oglitazone that predicted
01:33:32.680
that you would not die? They don't know. You know what the one thing that predicted that you wouldn't
01:33:37.860
die? Weight gain. So I jokingly say, look, you can either be a little fat and alive,
01:33:44.360
or you can be lean and dead. Which one you're going to pick? I think I go for being a little
01:33:48.400
bit chubby. But now that's not even a necessary comparison. You don't even need to make that
01:33:53.800
trade-off with a modern day GLP-1 agonist. Yes. And we've done this and we've published this.
01:33:58.300
If you tied my hands behind my back and said, Ralph, you can only pick one drug. I would pick
01:34:03.660
one of the newer GLP-1s. They're incredible drugs, but that's not what I'm going to do.
01:34:09.460
A little bit different story, but the answer is basically yes. Let me narrow that down a little
01:34:14.480
bit. If I had to pick two drugs, I would pick P-oglitazone with one of the newer drugs. And
01:34:22.040
for sure, if you had any kind of renal or cardiac disease, I'm going to pick an SGLT2 inhibitor.
01:34:28.920
But I would say, although this study will never be done, if you're a newly diagnosed diabetic and
01:34:34.120
you don't have any cardiac symptoms, why do you think that the SGLT2 inhibitor is not doing all
01:34:40.780
of the beneficial things in that newly diagnosed diabetic that it's doing in the people who get
01:34:46.500
into these studies who already have cardiac disease? So if you have a cardiac problem,
01:34:50.460
I put you on the SGLT2 inhibitor, you're less likely to have MI stroke, etc. It's doing good
01:34:55.300
things. It's doing, in my opinion, the exact same good thing in someone who I'm just diagnosing for
01:35:00.940
the first time when I put them on the SGLT2 inhibitor, but no one is ever going to do a
01:35:05.220
study. It's impossible. I'm going to take 1,000 people, you probably have to take 20,000 people
01:35:11.060
newly diagnosed, and then 10,000 go on SGLT2 and 10,000 on placebo. I'm going to follow them
01:35:18.900
for 20 years to see who's going to have their heart attack. No one's going to do that study
01:35:22.700
because they're going to get on all kinds of drugs. Yeah, that's never going to happen. But I also
01:35:27.080
don't think it needs to happen in the same way that... I agree with you.
01:35:30.680
In the same way that we saw, for example, PCSK9 inhibitors reduced MACE in people with secondary
01:35:37.440
prevention. Take people who had already suffered MACE, put them on a PCSK9 inhibitor, you secondary
01:35:43.420
prevention reduce subsequent. Well, of course, everybody's using these for primary prevention
01:35:48.260
now. That's effectively what you're saying is we already know the SGLT2 works for secondary
01:35:53.020
prevention. That may never get approval for primary prevention, but it probably justifies its use.
01:36:00.320
I agree with you a hundred percent. So just to make sure I'm synthesizing what you're saying,
01:36:04.480
Ralph, if you only get one drug and your price agnostic, GLP1 agonist. Yeah. If you get to add
01:36:10.840
a second drug, you're going to add PO. Yeah. If you get a third drug, especially if you care about
01:36:17.920
your heart, SGLT2. Yeah. SGLT2. And what's amazing is metformin didn't even make the top three in your
01:36:24.020
list. But it's number four, right? So here's my question. Given that metformin is free,
01:36:28.020
should we just be adding it the second we put on the GLP1? I don't have any problem with that.
01:36:32.820
Yeah. And also we have to be cognizant of the fact these newer GLP1s. So potent.
01:36:38.620
But they're a thousand dollars a month. Yeah. I want to ask you about that. So just again for
01:36:42.260
the listeners, right? Semiglutide is Gen 3. Trisepatide is Gen 4. Reditrutide is coming out,
01:36:48.400
assuming the phase three goes according to plan. And Kargi-Sema is the new NOVA one.
01:36:52.700
Yeah. Let's go back to Reditrutide. GLP1, GIP. And glucagon. Glucagon. Can you explain that in
01:36:59.000
the context of the octet where glucagon is going up? Yeah. I can, I think. It's not proven. So
01:37:06.780
remember I told you that insulin knocks down glucagon. So if I give you a GLP1 receptor agonist
01:37:14.220
and I kick out insulin and I get you well insulinized, any negative effect that might be related to
01:37:20.960
glucagon is going to be obviated. So that glucagon effect to drive hepatic glucose production
01:37:27.200
will be totally blunted by the insulin secretory effect. This is the other thing that bothers me
01:37:33.360
about these GLP1s. These are the best drugs in the world for losing weight. These are the best drugs
01:37:39.040
in the world for saving your beta cell. I told you that when you eat a meal, 70% of the insulin
01:37:43.940
that's secreted is coming from the GLP1 and the GIP. People have stopped talking about this effect on
01:37:49.620
the beta cell. I told you, if you want to look at type 2 diabetes, big problems, beta cell failure,
01:37:55.080
insulin resistance. These GLP1s, they're saving your beta cell. We've forgotten about it. We've
01:38:00.100
become so enamored with the weight loss. I don't want to downplay that at all because the weight
01:38:04.840
loss and the lipotoxicity, a huge problem that's causing insulin resistance. But people have forgotten
01:38:10.580
how powerful the drugs are on the beta cell. So when I give you this drug and they work on the
01:38:15.940
beta cell and they'll kick out insulin, any negative thing that glucagon's doing will be
01:38:19.660
totally negated. Now, you may see some good things that glucagon are doing that we couldn't
01:38:25.080
appreciate before. So what are the good things? Some people have suggested the increases thermogenesis
01:38:31.160
energy expenditure. I don't believe that. There are animal data. I don't believe this in humans.
01:38:36.820
I believe that it's exerting an interrectic effect in the central nervous system. That is,
01:38:42.200
I think, yet to be established. Pretty sure there are studies going on now at the Pennington Institute
01:38:47.820
and maybe also in Orlando where they have these chambers where you can-
01:38:53.140
Yeah. Yeah. So I think we'll get an answer about energy expenditure.
01:38:58.640
Yeah. I would be surprised if they're going to see a clinically meaningful increase in
01:39:04.020
I'm with you. I think it's all appetite. Here's another issue. It is very interesting. If you look
01:39:08.840
at all these big GLP-1 studies, cardiovascular, what's the reduction in cardiovascular events?
01:39:14.300
Almost uniformly 20%. Old dudes, exenatide, et cetera, liraglutide, new dudes, 20%. Even though
01:39:26.160
Much greater. I suspect in terms of cardiovascular benefit, there is a cap that once you've lost a
01:39:33.580
certain amount of weight and you've gotten a certain amount of lipotoxicity and all the good
01:39:38.520
things that these drugs are doing, you don't go beyond that. Even though you're losing more weight.
01:39:44.220
And also, if you look at the A1C, yes, Monjaro does drop the A1C a little bit more than semaglutide,
01:39:52.080
but they're both pretty powerful. Rituatide does a little bit more and does Cargisema do a little bit
01:39:57.780
more, but they don't do a lot more. So I also think there's also going to be somewhat of a cap
01:40:04.500
on how much you drop the A1C. You get two and a half percent drop. Do you need to drop at three?
01:40:10.440
So you're saying if a person shows up with hemoglobin A1C of nine and a half percent,
01:40:16.520
this is a person who hasn't come to medical attention soon enough.
01:40:19.840
And I'm going to give you the answer definitively, but I'm going to let you ask the question.
01:40:22.840
You're happy if they only go from nine and a half percent to seven percent. If they only had a two
01:40:27.740
and a half percent drop, you wouldn't try to get them down to six percent?
01:40:31.020
I would, and we've done the study. Old time guys, right? So this is called the Qatar study.
01:40:36.960
So there's this concept that's out there. And again, what drives me is science. If you understand
01:40:42.900
pathophysiology and there's an abnormality and you correct the abnormality, things get better.
01:40:47.020
So in the Qatar study, and there are 220 people or so in the study, to get into the Qatar study,
01:40:54.520
you had to be poorly controlled on metformin cell foliuria. So you had to have failed on this.
01:41:01.000
And the average A1C was about 10. And about a third of these people were symptomatic,
01:41:07.020
meaning they had polyuria, polydipsia, they were losing weight. And so the current concept is in those
01:41:13.060
people, you would put them on a mixed split insulin regimen. You would get rid of the glucotoxicity,
01:41:18.640
you get rid of the lipotoxicity, and you get their A1C down to six and a half. And then now you could
01:41:25.420
put them back on the oral medications or whatever. And now they respond because you got rid of the
01:41:29.800
glucotoxicity and lipotoxicity. We said, well, that may or may not be true. So we said, well,
01:41:35.060
half of these people are starting with an A1C above 10 will go on a mixed split insulin regimen
01:41:41.100
with a large union and rapid acting insulin. And the other half, I got to go on that old dude,
01:41:47.260
exenatide and pioglitazone, one that people don't like to use. Three years later, the A1C in the group
01:41:55.060
with the mixed split insulin regimen is 7.1%. And we're very good at insulin. Why couldn't we go
01:42:01.200
lower? Because we got into trouble with hypoglycemia. The A1C in the group treated with
01:42:07.520
exenatide and pioglitazone is 6.1%. Then we said, okay, look, we'll do a subgroup analysis. So
01:42:14.660
about one third of the people, we'll just look at the people who are symptomatic. The starting A1C is
01:42:20.280
12.2. Three years later, their A1C is 6.1. From 12? 12.2 symptomatic. On which combination?
01:42:29.680
Exenatide and pioglitazone. Without even metformin?
01:42:32.360
They had failed on metformin and SU to get into the study. So what we're saying, look,
01:42:37.760
if you have drugs that correct the insulin resistance, that's pioglitazone.
01:42:44.860
I can send you all the papers. It's all published.
01:42:47.420
I hope every single family medicine internist, everyone who ever takes care of somebody with
01:42:55.780
diabetes is listening. I hope so too. Because you're basically saying we can take these two
01:43:02.000
old cheap drugs and take someone from the most brittle type 2 diabetes. I mean, a hemoglobin A1C
01:43:14.280
You're going to go blind. You're going to have your toes amputated. You're not ever going to have
01:43:19.120
an erection again. And you're going to die of cardiovascular disease or kidney disease
01:43:26.180
These numbers that I'm telling you, they're right from the paper and it's a large, over 200 people.
01:43:29.820
And in a couple of years on two old cheap drugs, you're normal.
01:43:34.680
Yep. What makes these studies so solid is we have very sophisticated pathophysiologic
01:43:44.300
So the only pushback is those patients are going to have to gain a couple of kilograms.
01:43:48.440
But of course, if you're willing to now spend a bit more money and switch them from Gen 1 to Gen 3,
01:43:53.520
you're Gen 4, GLP-1 agonist and GIP, then all of a sudden you ameliorate that and you get all the
01:44:02.560
I would wonder if you add metformin, you almost cancel out the weight gain a little bit because
01:44:07.320
you might get a little bit of the GI improvement and you get the two to three kilos of weight loss
01:44:12.600
These drugs are so powerful when you put them with pioglitazone. I mean, you lose almost the same
01:44:17.180
amount of weight. They're huge in terms of getting you to lose weight.
01:44:22.340
This is called the Qatar. It was done in Qatar.
01:44:26.060
The country. And I need to give credit to Dr. Bahamut Ablugani, who's been sort of my
01:44:31.320
co-worker in all of these studies. And Bahamut's on the faculty at UT in our diabetes division.
01:44:38.460
Can we at least assume that the Gulf states are paying attention to this? A, the study was
01:44:43.100
done in Qatar. B, the Gulf states are disproportionately ravaged by type 2 diabetes.
01:44:50.920
They are. And I can tell you we have a big program that's going on there as well as in
01:44:55.580
Kuwait. And we actually have a formal cooperative agreement with the Kuwaiti people. So at the
01:45:02.500
Dasmin Diabetes Institute, we have trained them. My people have been there, trained them how
01:45:09.020
to do these insulin clamps and sophisticated metabolic studies, and they take care of the
01:45:13.780
patients. So here's another thing that's pretty exciting that we're doing. And again, it's looking
01:45:18.600
for genes that cause diabetes. So you eat a meal, okay, you eat a meal, your glucose goes up.
01:45:24.740
That secretes insulin. There's amino acids in the meal. That secretes insulin. And GLP-1 goes up,
01:45:31.040
and that secretes insulin. So now, when you eat a meal, there are already three stimuli.
01:45:35.520
And now you're looking for a gene or a set of genes that might be associated with beta cell
01:45:41.980
failure when you have three stimuli. Now, that's going to be pretty confusing. So what we said,
01:45:47.580
maybe what we should do is that we should do a three-step hyperglycemic clamp. So we give you
01:45:53.680
three steps of glucose, and we can get beta cell sensitivity to glucose. From the slope,
01:46:00.040
I give you a little rise in glucose, another rise in glucose, another rise in glucose. I see how
01:46:04.200
much C-peptide comes up. The slope of that curve is, that's beta cell sensitivity to glucose.
01:46:08.740
And then the M value is where it hits the axis?
01:46:11.640
Then I can get glucose. But this is just, now I'm going to focus on the beta cell,
01:46:15.380
because the hyperglycemic clamp is just for beta cell function. And then after that,
01:46:19.620
now I'm going to give you GLP-1 infusion, and I'm going to see how much insulin comes out.
01:46:23.780
And then after that, I'm going to give you an balanced amino acid infusion. I'm going to see
01:46:29.260
So you can sequentially measure the different...
01:46:31.280
Three different stimuli. And now what we see is different loci. Some are associated with the
01:46:37.140
defect in glucose. Some are associated with the defect in amino acid. So again, the more you can
01:46:43.240
refine the phenotype, the more likely you are to identify defects that are there at the level of
01:46:50.660
Let's go back to the Qatar study for a second. How many people were in that study?
01:46:53.380
About 220. Big study when you're doing... These insulin clamp studies and these kind of measurements
01:47:00.800
Let's see. I would say the one and a half year data were probably about 2018. And the three year
01:47:09.380
data, I would say 2021, 22, something like that. I can send you all the references.
01:47:14.840
Yeah. We'll link to all of these in our show notes for folks. Just simply phenomenal.
01:47:18.800
Let me ask you a question. If you take an individual with type 2 diabetes or insulin resistance,
01:47:24.100
and you presumably collecting urinary C-peptide for 24 hours is the best surrogate for total
01:47:33.760
If you could quantify total area under the curve of insulin for a person, and then you gave them
01:47:39.360
a GLP-1 agonist, is total insulin going up or down?
01:47:43.320
Depends. Because you have competing factors going on here. And I'm not trying to be elusive because
01:47:49.900
what I'm telling you is actually real. It's what happens. The drug is going to kick out insulin
01:47:54.720
and C-peptide is going to go up. And now the glucose is going to come down.
01:47:59.860
And then you need less. So depending upon the relationship, when you look in absolute terms,
01:48:07.000
the C-peptide and insulin levels actually may be lower. But now when you express how much C-peptide
01:48:13.580
comes up, per the rise in glucose, huge increase. So you always have to have something that you
01:48:19.940
compare it to, and that's the increment in glucose. And anytime you look at how much insulin comes out,
01:48:25.140
or C-peptide, which is another confusing factor, which I'll mention in a second,
01:48:29.280
you always have to relate it to the glucose area. When you do that, huge increase in beta cell function.
01:48:35.580
The other thing you have to be very careful about is you need to be measuring C-peptide,
01:48:39.240
not insulin. What we've shown, and this is a compensatory mechanism.
01:48:43.640
Maybe just tell folks, I threw out C-peptide as though everybody knew what it is. That's a mistake.
01:48:48.280
Tell people what C-peptide is and what its relationship is to insulin.
01:48:50.720
Yeah. So when you ingest a meal, there's a precursor that contains both C-peptide and pro-insulin.
01:48:57.380
And so you split off C-peptide and you split off insulin. And they both come out in a one-to-one
01:49:03.100
molar ratio. The problem is half of the insulin that comes out is taken up by the liver.
01:49:08.280
So you never see it in the circulating bloodstream. The C-peptide is not taken up by the liver.
01:49:13.800
So everything that comes out, you see in the circulation. So when we want to know how much
01:49:18.900
insulin was secreted, we actually don't measure the insulin. We measure the C-peptide.
01:49:23.880
And that's the true measure. Now, the other confounding feature here is, and we've shown this,
01:49:29.500
and this has now been reproduced by many other people, is that when you become insulin resistant
01:49:34.480
and diabetic, your beta cells don't secrete enough insulin. That's one of the big defects.
01:49:40.020
How do you compensate? You don't destroy the insulin that's secreted. So the degradation of
01:49:45.360
insulin becomes markedly impaired. So you can have a high insulin level, either because you secrete
01:49:51.600
too much insulin or because you don't destroy the insulin. So measuring the insulin level is not a good
01:49:57.820
measure of beta cell function. If you want to know about insulin secretion, measure the C-peptide
01:50:04.220
and express it per rise in glucose. It gets a little bit more clouded because your beta cell also
01:50:11.380
can recognize how insulin resistant you are. And so it knows, look, if you're this insulin resistant,
01:50:17.180
I need to secrete more insulin. If you're very insulin sensitive, like you're a lean person
01:50:21.680
with normal glucose tolerance, you don't want to secrete much insulin, you get hypoglycemic.
01:50:26.440
How does your beta cell recognize that? Well, that's somewhat controversial. I can give you my
01:50:30.980
thoughts about it. But in either case, measuring beta cell function is not just simply measuring
01:50:36.360
insulin. That's probably bad. Measuring C-peptide is better. Measuring C-peptide per rise in glucose
01:50:41.480
is better. And then for some way or another, if you can express this all per insulin resistance,
01:50:46.320
this is called the disposition index, something that Dr. Stephen Kahn developed with Daniel Port
01:50:52.680
many, many years ago. So simply looking, as I said, as insulin or trying to do an OGTT and come up and
01:51:00.840
say, you know how the beta cell is working, that's not so good. And that's why I say in the Qatar study,
01:51:06.880
in the EDIC study, we're doing such sophisticated measures of insulin sensitivity and beta cell function,
01:51:12.600
you do 350 people, that's like doing one of these big cardiovascular studies with 5,000 people in it.
01:51:18.780
The pathophysiology will always tell you the truth, in my opinion. If you know what the problem is,
01:51:25.840
and you correct the problem, the A1C is going to get better. ADA does not emphasize pathophysiology.
01:51:32.940
You had Jerry Shulman on. I'm sure Jerry will tell you, he and I think very similarly. You understand
01:51:38.140
what causes a disease, and then you come with the treatment that will make it work.
01:51:42.600
Do you have any concerns with long-term safety or anything other than simply the economics of
01:51:50.060
the GLP-1s in this current generation? Again, huge, huge leap forward between
01:51:56.620
liraglutide and semaglutide. And I've discussed briefly elsewhere on the podcast what the roadmap
01:52:03.320
looks like for how many of these drugs are in the pipeline. There seems to be no end in sight.
01:52:09.100
And we're going to look back at semaglutide and say, God, that thing was pedestrian.
01:52:14.260
Give us the bear case. What should we be concerned with? What should we at least looking out for?
01:52:18.660
I would say overall at the present time, I would consider these drugs to be quite safe.
01:52:25.860
The major issue is you have to go slow because of the GI toxicity. Where is the controversy
01:52:31.060
involved? And it's something that I'm involved with myself. When you lose 20 or 30% of your body
01:52:38.880
weight, you lose muscle mass. Now, I just gave a talk on this to one of the pharmaceutical companies
01:52:44.480
that are involved in this area. I'm not going to name the name of the pharmaceutical company,
01:52:49.120
but I started off by saying, look, here is now a study with real data. This is a gastric bypass
01:52:55.840
surgery study, room-wide bypass. And the people lost, I think it was 33% of their body weight.
01:53:01.680
And their lean body mass came down quite significantly. One of the problems is people
01:53:06.020
measure lean body mass, and that's not a real measure of muscle mass. In fact, it can be a very
01:53:10.580
bad measure. You should measure muscle mass. But let's assume that the lean body mass largely reflects,
01:53:17.700
it's a reasonable assumption, muscle mass. So muscle mass came down. Why is that so bad?
01:53:22.580
How much did it come down? Because if total body mass came down by 33%, but three quarters of that
01:53:31.400
mass was fat, and only one quarter of that was lean, we would consider that acceptable.
01:53:38.700
And this is where the controversy is, because no one has really measured muscle mass. We're doing it.
01:53:46.540
MRI. It's gold standard. But now, I said, look, in this study,
01:53:51.920
they measured absolute strength. You can do grip strength or leg strength. And absolute strength
01:53:59.720
Were these patients exercising during the period of their weight loss?
01:54:03.780
No, no, no. No, no, no. No. Then they said, let's express strength per weight loss.
01:54:09.540
Whew, up by 50%. Per appendicular, it goes up by 50%. And then they said, how far can they walk?
01:54:16.900
They went from walking 200 yards to two miles. And then they said, one of the things is how many
01:54:22.340
times can you get up out of a chair in a certain period of time? It increased like three or four
01:54:29.080
Yeah, of course, which is heavily dependent on weight as well.
01:54:32.400
But in absolute terms, did VO2 max get better? Not necessarily.
01:54:39.080
Okay. That's counterintuitive, by the way. Normally when you lose weight, VO2 max in liters
01:54:44.420
per minute does not improve because you have less metabolic tissue.
01:54:47.820
But here, for whatever the reasons are, maybe all of the fat that's pushing on your lungs so you
01:54:53.920
can't oxygenate, the epicardial fat that's not allowing your heart to contract, the fat that's
01:54:59.580
in the heart that's causing myocardial lipotoxicity, which I believe is real. These things are all
01:55:04.780
changing in a positive way. So again, it's a balance. Of course, they don't like this.
01:55:12.380
Well, because now the companies are all looking at developing drugs that will preserve the muscle
01:55:17.080
mass or increase the muscle mass. But basically what I'm saying is that, look, it's lean body mass.
01:55:22.580
We have to say it's reflecting muscle mass. Everything gets better. The patient feels better.
01:55:27.800
They can walk better. They feel stronger, et cetera, et cetera. Why are you so worried about
01:55:31.140
muscle mass? I look all these gloomy faces because they're all developing myostatin inhibitors or
01:55:36.900
event. And then the next slide comes up and says, retort. Here's a good thing. So now if you lose all
01:55:43.920
of this body weight and you improve insulin sensitivity in muscle and you improve it in the heart and there
01:55:49.600
are cardiovascular benefits and you correct the improvement in all of the cardiovascular risk factors,
01:55:56.480
now even though you've lost muscle mass, if you've improved insulin sensitivity, there may be an
01:56:04.380
enormous benefit of seeing the improvement in the muscle insulin sensitivity even though you've lost
01:56:11.220
muscle mass. And they do have some concerns about these drugs, these myostatin inhibitors that actually
01:56:18.140
may have some negative effects in the heart. And my suggestion is actually you may find a big
01:56:22.920
improvement in myocardial function. Where are myostatin inhibitors in their development?
01:56:27.900
Phase two. Of course, I think we've talked about myostatin before on the podcast. When you inhibit
01:56:32.760
myostatin, you increase the expression of striated muscle of which cardiac is striated.
01:56:38.780
It works through the event in 2A and 2B system. Do you think that's a more promising pathway than the
01:56:44.280
folistatin pathway where folistatin... Yes, I do. Increasing folistatin inhibits myostatin,
01:56:48.960
but this is a more direct way to go about it. This is a more direct way to do it. So you can either have
01:56:52.840
their antibodies by Grubab to myostatin or you can interfere with the signaling receptor itself.
01:57:00.880
And we think that this can still be effective in a fully developed and mature adult. I mean,
01:57:05.180
clearly this would be effective during development. And we see that in the animal work. How effective
01:57:10.680
is it? A lot of the animal work is sort of a caricature stuff. It's knockouts, right? They take
01:57:14.780
myostatin knockouts and they look like bodybuilders. But if you take a mature chicken or a mouse that's
01:57:20.360
two years old and you give it a myostatin antibody, how robust is the response? Even more so,
01:57:26.060
what about in a human? We don't know the answer to that. So what the phase two studies,
01:57:30.460
obviously the toxicity passed in phase one. Yes. There doesn't seem to be any adverse effect
01:57:37.080
of these drugs or they wouldn't get through phase two. And there are actually some fairly large
01:57:42.280
phase two studies. What's the indication? Is it sarcopenia? I don't know. The FDA,
01:57:47.460
if you have a sarcopenic disease, there are criteria that the FDA has established if you
01:57:53.320
want to develop a drug that you have to meet certain criteria. I'm not an expert in this.
01:57:58.040
I can't tell you exactly what these criteria are, but they are pretty well established. Now for these
01:58:04.080
kind of people, and I'm going to come back, you asked me about lean people. I'll come back to that in a
01:58:07.560
second because this is really an issue. Let's say I put you on a GLP-1 receptor agonist and you lost
01:58:14.020
25% of your body weight. And I put you on a myostatin inhibitor and that prevented the muscle loss.
01:58:20.960
Didn't increase it, but just prevented it. But that would be ridiculous. I mean,
01:58:25.240
if you took a 200 pound individual who's 30% body fat, they've got 60 pounds of adipose tissue on them.
01:58:34.280
If you took 25% of their body weight off, you take them down to 150 pounds, but you're telling me
01:58:40.920
potentially we prevent any deterioration of lean mass. That means they're down to 10 pounds of fat
01:58:47.460
mass on 150 pound frame. I'm making an assumption. Okay. This is remarkable. Right. So let's say that
01:58:53.220
happened. What would be the FDA's criteria? I'm going to give you approval for this drug.
01:58:59.960
I think the FDA would ask that you've also improved function in some way. And the function
01:59:07.640
would have to be determined through absolute strength, not relative strength, would be my
01:59:12.160
guess. I don't know the answer to this question. Because the way I think about these drugs is less
01:59:17.960
about that situation. It's more in the sarcopenic adult. This is the lean, particularly the older
01:59:24.080
person. That's right. That's right. This is the elderly individual who's sarcopenic and whose fall
01:59:28.700
risk is enormous. And their risk of fall and morbidity and mortality is very high. And in that
01:59:36.300
individual, I don't think the FDA will be satisfied with simply an increase in lean body mass unless it
01:59:42.300
is accompanied by strength. Now, I think that some of the tests that are used here are silly. I think
01:59:48.460
the six-minute walk test should be folded up, discarded, put in the wastebasket, and never
01:59:53.360
discussed again. It is such a stupid test. They do it all the time. I know they do. And it just makes
01:59:59.540
me want to scream. Yeah. We need much more rigorous tests than a six-minute walk test. We need a test
02:00:05.740
that is actually more of a submaximal test. So if we're testing cardiorespiratory fitness or some sort
02:00:12.400
of peak aerobic fitness, we have to do more than walking. And if we're testing strength, I much prefer grip
02:00:18.040
strength, leg extension, bench press. Again, these can be done with machines. They can be done very
02:00:23.160
safely. But we really need to test strength. You see, you're raising very important and critical
02:00:28.680
issues because there are many, many companies that are going ahead with these drugs that increase
02:00:33.760
muscle mass. But to me, okay, increasing muscle mass, what does that mean? There needs to be some
02:00:39.760
functional translation of that. There could be other functional benefits that exceed strength. For
02:00:45.220
example, glucose disposal could be a functional benefit. Insulin sensitivity. That's the one I
02:00:49.260
put at the top of the list for them. Get rid of the insulin resistance. The FDA won't give them
02:00:53.360
credit for that, I don't think. Yeah. But I think that, again, it's harder to tease out because there's
02:00:57.600
more moving pieces and they might argue there are easier ways to increase insulin sensitivity and
02:01:01.560
glucose disposal. But one way to think about this is to go back to what if you did it the old-fashioned
02:01:06.500
way? What if you got in the gym and lifted a bunch of weights? That's been done. Yeah. And it
02:01:10.900
increases insulin sensitivity and functional strength. And so the question is, can we replicate
02:01:15.000
that pharmacologically? And that is actually exactly the way I ended my discussion to these
02:01:21.000
people. I showed them what resistance training did. And if you could show what resistance training did
02:01:26.760
with your muscle mass increase, then you'd have something. But you need to design the studies
02:01:32.360
appropriately. And as I said, and as you said, I don't know what the criteria are going to be that
02:01:37.800
the FDA uses to judge these things. They do have a sarcopenia set of criteria, but that's a very
02:01:43.960
different group of people that we're talking about. But this comes and hits home to one of the things
02:01:48.820
you asked me earlier. What about the lean person who's 80 years of age? Is this the right drug for
02:01:54.520
that person? I don't know. Maybe not. But now let's say you have a healthy 80-year-old person and
02:02:02.180
everybody in the family lives to be 105 and they have diabetes. Well, they're at risk to the toxic
02:02:08.580
effects of hyperglycemia. Would it be reasonable to treat that person? We know this powerful effects
02:02:14.700
on the beta cell. I would say it would be quite reasonable, but I think you need to monitor what's
02:02:18.940
happening to their weight and other features. Here's a bigger issue. Childhood obesity. You are
02:02:25.820
obese when you're four years of age. You're going to be obese when you're an adult.
02:02:29.220
And your life expectancy will be significantly shorter. Biggest. And your quality of life will
02:02:34.760
be significantly reduced. And you're going to get diabetes. Now, make it even better.
02:02:38.300
Adolescents, these young kids with diabetes, they don't respond to any of the drugs.
02:02:43.400
What is the prevalence of type 2 diabetes in under 18? It's increasing, but I would say maybe around
02:02:49.500
4 or 5%, something like that. One in 20 teenagers has type 2 diabetes?
02:02:55.900
I'm biased by San Antonio because we have more people with type 2 diabetes in our clinic.
02:03:01.600
You could say potentially in San Antonio, one out of 20 teenagers.
02:03:07.620
And for sure, pre-diabetes. And I'll tell you about the pre-diabetes study that we did.
02:03:11.100
And we know these studies are out there. These kids and this big NIH-sponsored study,
02:03:17.020
they don't respond to metformin sulfonylureas. They don't respond to any drugs very well.
02:03:23.160
The first study has just come out. They respond better. It's a liraglutide study.
02:03:29.180
Just clinically, if you're in the clinic and you're using the best drugs you have available.
02:03:37.640
They're so insulin resistant, much more so than adults. These are well-published studies.
02:03:42.860
Is this really a selection bias where for someone to develop type 2 diabetes as a 16-year-old,
02:03:49.540
the underlying genetics and pathology are so severe that the current crop of drugs are the
02:03:55.460
problem? As opposed to when you take the current crop of drugs and you apply them to people who
02:04:02.420
All three. Because I'm going to add one more. Genetic predisposition. So Hispanic population,
02:04:08.480
huge problem. Obesity. All of these kids are huge.
02:04:12.380
So you don't have the lean diabetic phenotype in this age?
02:04:15.680
No, not in these people. And then the drugs don't work very well. So all three of these
02:04:20.220
things. And what now has come, it's called the RISE study. And as these kids have been followed up,
02:04:25.840
they're starting to develop kidney disease. They're even, I'm told, a couple of people have had MIs in
02:04:30.000
their 20s. They're incredibly difficult to control.
02:04:33.860
What do you think? I mean, yes, we're going to argue that these kids are,
02:04:36.680
this is due to what they're eating, but what is it in the environment that is so obesogenic to these
02:04:44.400
I'll come back to this in a second, but I want to raise the issue now. Let's say you're 16 and you
02:04:50.080
don't met form and solve. Your A1C is nine. You're going to put someone on Manjaro and they're going to
02:04:55.020
have to take this for the rest of their life. Because as soon as you stop the drug. So this is
02:04:59.720
what I treat the person. Of course, I can't let the A1C nine.
02:05:03.220
If you take that 16-year-old with a hemoglobin A1C of nine and you give them Manjaro,
02:05:09.540
I think that if they can afford the drug and they stay on the drug, the three big ifs,
02:05:15.380
if the doctor knows what to do, I know what to do. If the patient will cooperate with you,
02:05:20.380
if you don't, they'll lose every time. And if they can afford, if you can satisfy those three Fs,
02:05:25.800
that person we know from the studies would be pretty well controlled.
02:05:28.700
What fraction of insured patients will have coverage on Manjaro if their A1C is nine?
02:05:39.100
Yes, if you have diabetes. The Manjaro coverage I think is pretty good if you have diabetes.
02:05:43.560
If you have obesity without, that's a whole different issue. Should you be treating these
02:05:47.480
young kids? Obesity is a disease. They've got all kinds of problems. Should you put these young
02:05:52.420
kids on these newer drugs? And knowing that all I did is change you from food addiction to drug
02:05:58.240
addiction. I didn't do anything else. It's almost like alcohol addiction. There are drugs that things
02:06:04.240
I can give you that can help you, but they tend to relapse. Food addiction, I put you on the drug,
02:06:10.100
you lose weight. You stop the drug, you regain the weight. This is a huge public health concern.
02:06:15.260
It's almost way beyond my capacity because finances are involved here. Can we afford to treat 42%
02:06:23.020
of the people in the U.S. are obese? Or is there some way amongst the 42% we can define who are the
02:06:30.160
people who are insulin resistant? Who are the people who have the metabolic syndrome that we know
02:06:34.020
they're at risk, that we can treat them? My guess is that the great majority of that 42% of the people,
02:06:39.180
can we treat all of those people? And moreover, are they going to stay on the drug? We know on average
02:06:44.300
what the data is saying. I put you on the drug. We don't know all the reasons why,
02:06:49.480
but within a year, half of the people stopped the drug. Yeah. And it's probably a combination
02:06:53.040
of cost and side effects. Yeah. And my patients very commonly tell me,
02:06:57.820
I enjoy eating and I can't eat anymore. Some people just tell me they just want to eat. So I'm
02:07:04.120
going to get fat again. So I'm going to eat. Some is GI side effects and some is cost. $1,000 a month
02:07:10.100
is a lot of money for people. Yeah. Of course, this begs the question,
02:07:13.160
will the next generation of weight loss drugs be true uncoupling agents where you can basically eat
02:07:19.580
as much as you want and they're going to create so much mitochondrial uncoupling and thermogenesis
02:07:24.640
that you're truly going to see this increase in non-voluntary energy expenditure. And of course,
02:07:31.580
not have the GI side effects. But before we go on to the next thing I want to chat about,
02:07:36.500
and I just kind of bring it back to this question, which everybody wants to understand this,
02:07:40.680
which is what has changed so much in the last 30 years that has created this epidemic. And
02:07:47.740
everybody has their favorite pet theory for what it is. It's the sugar, it's the carbs,
02:07:53.200
it's the plastics, it's the video games, it's the internet, it's the whatever. Perhaps suggesting
02:07:59.080
that it's many, many things. What is your best explanation for what's going on?
02:08:04.120
I would say all of the above, processed foods, calorically dense foods, lack of exercise are
02:08:10.740
critical. But these are, I would say, the stimuli that has done something, that's changed the
02:08:17.560
neural circuitry in the brain. So yes, there's a stimulus. And because now you've been oversubscribed
02:08:24.120
to these stimuli, that's now initiated a process in the brain, which is going to be a self-fulfilling
02:08:30.040
process. This is something that I'm very interested in, Dr. Peter Fox and I at the Health Science
02:08:35.860
Center. But if you go through the literature, and we've published on this as well, in the areas of
02:08:41.820
the brain that control food intake, and I'm not talking about the hypothalamus, that kind of
02:08:46.240
regulates your basal energy intake, what you need to be, keep your BMI of 25, do what you do during the
02:08:52.660
day. But what is it that makes your BMI go to 35? That's all related to the hedonic areas in the brain,
02:08:59.100
the putamin, the amygdala, the prefrontal cortex, etc. And then when you do structural MRI, what you
02:09:07.040
can show is that those areas in the brain, the gray matter is shrunk down. And if you now map the
02:09:12.940
neural circuitry, which Peter Fox has been involved with, you can see that there's clear disruption using
02:09:19.500
functional MRI of the neural circuitry in the brain. We have a particular interest in defining
02:09:25.340
where this dysfunction occurs. And we have some ideas, which I'm not going to go into, but how we
02:09:33.040
might be able to sort of reprogram the brain. And in concert with this, these are not data, but these
02:09:40.360
are data that are published in the literature. And I think I mentioned this earlier. If you do an insulin
02:09:45.220
clamp, okay, I told you that in your eye, your brain doesn't respond by taking up glucose. But in people
02:09:52.360
who are obese, actually almost in proportion to how obese you are, in these areas in the brain,
02:09:58.800
the hedonic areas, there's a marked increase in, it's called fluorodeoxyglucose, which is the pet
02:10:04.380
radioisotope trace that we use in these areas. And that correlates inversely with the muscle insulin
02:10:10.180
resistance. The more insulin resistant they are in the muscle, the more FDG glucose uptake there is in
02:10:16.080
the brain. Now, this is very interesting, because what it's saying, there's a connection. That somehow
02:10:21.440
or another, we believe that the brain is talking to the muscle, or the muscle is talking to the brain,
02:10:26.840
and that somehow or other, the brain is playing a very important role in the development of the
02:10:32.960
insulin resistance. And that in large part, this deranged neurocircuitry, which is related to food
02:10:39.600
intake, is now making you overeat. And as you overeat, then all of the things that we know,
02:10:45.840
that we've studied, that other people have studied, that go with lipotoxicity, you put fat in the muscle,
02:10:51.800
you're insulin resistant. You put fat in the liver, you got NASH and NAFLD. What people have totally
02:10:56.440
overlooked, you put fat in the kidney, you get kidney disease.
02:11:01.200
So you've been in San Antonio since the late 80s. When did you really start to notice this was a
02:11:07.020
problem, at least in your community? Almost instantaneously.
02:11:12.140
We can't blame video games. We can't blame social media, because that wasn't going on in the late
02:11:16.780
80s. I never saw fat kids at Yale. I was on the faculty from 75 to 88. And I kind of thought back,
02:11:24.760
now I would say New Haven's not a large Hispanic, but it's more African-American. But I don't remember
02:11:30.720
seeing 12-year-old kids with type 2 diabetes. And when I came here, and I remember this very distinctly,
02:11:40.280
they're saying, oh, you're crazy. You don't see kids with type 2 diabetes. Believe me, I see them.
02:11:45.980
What did your colleagues at San Antonio tell you as far as when they started to notice that in the Hispanic kids?
02:11:53.520
I don't know that I can give you a specific time that they told me, except they knew it.
02:11:57.660
So, okay, what about in non-Hispanic kids? Because if the Hispanic kids are genetically
02:12:02.420
predisposed to this, then the question becomes, when did you begin to see this in African-American
02:12:09.820
So, we don't have a large African-American population here. But like in Philadelphia,
02:12:15.120
there's a lady, Sylva Arslavian, she sees the same thing. And she sees, I think it's a significant
02:12:21.540
African-American population. So, I think that in certain ethnic minorities, where the genes for
02:12:27.300
diabetes are enriched, those are the populations that are predisposed.
02:12:33.080
And do you think this is mostly an energy balance issue, and therefore, it's mostly a food environment
02:12:39.180
No, I think it's both. So, I told you I'd come back to the genetic study that we did.
02:12:43.340
An Italian fellow was with me, Giovanni Gulli, a long, long time ago here in San Antonio. We wanted
02:12:49.180
to know, what is the earliest defect that you can see in people who are going to develop type 2 diabetes?
02:12:55.700
So, he said, okay, in the Hispanic community, it's very common to see mom and dad with diabetes.
02:13:01.860
And it's very common to see a lot of children in these families. So, he said, why don't we go look
02:13:06.600
at the children? And let's see if we can define, because they're at high risk. And if you have mom
02:13:12.760
and dad with diabetes, you probably have a 70, 80% chance if you're Hispanic, if you're born in that
02:13:17.740
family developing diabetes. It was very easy to find the children. The problem was we couldn't find
02:13:22.340
lean children. So, it took us a while, because if you're obese, then you got the lipotoxicity.
02:13:28.380
So, we finally found them. This is a JCI paper, I believe. And so, we did an insulin clamp. They're
02:13:34.420
as resistant as their parents. They have normal glucose tolerance. Why? Because their insulin
02:13:38.980
levels are astronomical. And then we do a muscle biopsy.
02:13:43.280
Oh, they're like two times normal. Even higher sometimes. We do a muscle biopsy. The same
02:13:52.220
How many of the tyrosine kinase defects do they have?
02:13:55.960
It starts at IRS-1. Insulin binding to the receptor is okay, just like their parents.
02:14:01.180
The ability to activate the insulin signaling pathway at the level of the IRS-1, it's already
02:14:14.340
Well, no. It's IRS-1. You can't tyrosine phosphorylate it. You cannot activate PI3 kinase.
02:14:21.900
And then the other thing, Jerry and I have both done this in somewhat different ways. I'm
02:14:27.000
talking about Jerry Schulman. He uses NMR by looking at phosphate derivatives. Even though
02:14:33.580
I believe the primary defect is in the signaling pathway, there's clearly severe impairments
02:14:39.100
in glucose transport and phosphorylation. His work would suggest that the primary defect
02:14:43.480
is at the level of glucose transport. We developed a novel triple tracer technique using three
02:14:49.340
isotopes infused into the brachial artery. We believe that the primary defect is at the
02:14:54.320
level of hexokinase and phosphorylating glucose. We kind of agree to disagree because we can't
02:15:00.360
do the study. We'd have to do the MRI study at the same time we're doing the triple tracer
02:15:04.400
technique. In addition to the insulin signaling defect, there's a severe defect in glucose
02:15:11.640
Let's just make sure people understand this as we're kind of getting into some biochemistry
02:15:14.820
here. When glucose enters the cell passively through the GLUT4 transporter.
02:15:24.240
Yeah. The first step to that is hexokinase, which takes a phosphate off ATP and puts it on
02:15:29.860
the sixth position if I'm not mistaken. And it's a specific type of hexokinase,
02:15:34.180
so it's hexokinase 2. Because there's a different one in the muscle and the liver,
02:15:37.980
correct? That is correct. So Jerry would say the primary defect is in GLUT4, the transporter.
02:15:45.020
I would say, yes, that is severely impaired. Remind me what Jerry believes is wrong with
02:15:49.580
the GLUT4 transporter? That it doesn't work normally.
02:15:52.580
I thought it worked fine. It's just not getting the signal to work because of IRS-1.
02:15:56.540
That's where the controversy is. We were the first to show this defect in muscle. In fact,
02:16:01.120
we're the only people I think that are showing this in human muscle. It's been shown in rats,
02:16:04.820
et cetera. To me, metabolism in rats and mice is so different. This is all people data.
02:16:10.740
So you're saying it's possible that just having the IRS-1 problem is enough. It's also possible
02:16:16.960
that even if IRS-1 is functioning reasonably, if GLUT4 is not getting up, that's the problem.
02:16:24.660
And then it's also possible that even if all those things work, if you don't get hexakinase
02:16:28.920
to phosphorylate glucose, you back up the whole system.
02:16:33.260
And I can show you that there's a primary defect in pyruvate dehydrogenase and glycogen synthase.
02:16:38.700
This comes back. I have an ominous octet for the insulin resistance. That's why people don't
02:16:43.620
understand. Look, there are eight organ sort of things that are a problem. There are eight problems I
02:16:48.980
can show you within the muscle. Why do you think one drug is going to correct all these problems?
02:16:52.460
We need drugs to work on the beta cell. We need insulin sensitizers. We probably need different
02:16:57.280
types of insulin sensitizing drugs. We need drugs that reverse the lipotoxicity. And will we ever
02:17:03.580
have a single magic bullet that corrects all of these? Probably not until we discover the genetic
02:17:10.760
basis. And remember, I said that diabetes is a heterogeneous disease. In diabetes metabolism reviews,
02:17:17.360
I would say 30 years ago, I wrote a review article that said, I can put a defect in the muscle and
02:17:25.180
reproduce diabetes. I can put a defect in the liver and reproduce diabetes. I can put a defect in the
02:17:31.620
fat cell and reproduce diabetes. I can put a defect in the beta cell and reproduce diabetes. And I went
02:17:38.580
back and read that. And I said, I can put a defect that starts in the brain and reproduce diabetes.
02:17:47.140
All these defects we've been talking about, they're already there.
02:17:50.320
So you put that defect in the fat cell, they can look lean.
02:18:00.060
There's this, Phil Scherer will love me for saying this.
02:18:02.180
He's the top guru in adipocyte metabolism up in Dallas.
02:18:08.900
There's a specific defect in the glucose transporter and white adipose tissue.
02:18:27.620
And not only that, now that they define this in people in this paper,
02:18:32.400
they then went to the animal model and they knocked out the gene that's causing the defect
02:18:36.280
and they reproduce diabetes in the normal mouse model.
02:18:39.480
Ralph, I want to close by bringing it back to something that people can do
02:18:42.640
to help understand if they're at risk, either lean or otherwise.
02:18:46.780
We talked about it at the outset, but didn't go into it in detail, which is the OGTT,
02:18:52.440
Now, again, none of us have the privilege of being able to use a euglycemic clamp,
02:18:56.080
both clinically as physicians or as experienced as patients.
02:19:00.800
So we're going to have to kind of rely on other things.
02:19:08.920
We're going to have to rely on hemoglobin A1C, although I find that to be a particularly
02:19:15.100
At the individual level, I find it very unhelpful.
02:19:20.800
But boy, the correlation between hemoglobin A1C and realized glucose levels is pretty weak.
02:19:27.140
But let's talk about the OGTT, because this is not a test that is done frequently.
02:19:33.320
And I'd love to have you walk us through the interpretation of the following.
02:19:41.240
You got a person who starts out, all of these people are going to start out normal.
02:19:43.920
They're going to start out with a glucose of 90 and an insulin of six.
02:19:47.180
At 30 minutes, this is after 75 grams of oral glucose.
02:20:16.820
As a pre-diabetic state, this is a very insulin-resistant person.
02:20:21.960
And two hour later, hypoglycemia is a reflection of the beta cells' early insulin secretion.
02:20:35.620
This is a person, by the way, with a perfectly normal hemoglobin A1C.
02:20:38.940
And this is a person who gets passed all the time as totally normal.
02:20:46.800
Your hemoglobin A1C is normal and your insulin is 6, even if the doctor's checking insulin.
02:20:50.800
But as you point out, the thing that trips you off is not their glucose.
02:20:57.400
It's 90 was how high the insulin was at 30 seconds.
02:21:01.460
And of course, they overshot, which is why they become hypoglycemic.
02:21:22.020
But just to be clear, these are almost real cases, by the way.
02:21:29.280
The best predictor of who's going to get diabetes is a one-hour glucose greater than 155.
02:21:34.160
And this is from prospective data from the San Antonio Heart Study, also from the Botnia
02:21:39.700
Study, where these people have been followed up.
02:21:42.340
We were the first people to publish this, oh, I'd say 7, 8, 9, 10 years ago.
02:21:46.740
There have been, I'd say, at least 15 to 20 studies that have reproduced what we showed
02:21:57.640
And that's a great predictor of type 2 diabetes, regardless of all the other metrics.
02:22:02.060
And if you also happen to be hypoinsulemic, that adds more to the predictive value.
02:22:09.920
That's a huge predictor of whether you're going to develop diabetes or not.
02:22:13.680
That's from the San Antonio Heart Study, and that's also from the Botnia Study, and also
02:22:22.900
This is a person who has a delayed onset of insulin.
02:22:26.660
So in other words, they start out normal at 90 years.
02:22:31.740
So what's going on in this person where 30-minute insulin does nothing, glucose rises, and then
02:22:37.540
at an hour and 90 minutes, the pancreas kicks on and starts to dispose of glucose.
02:22:45.400
And one of the earliest things you can detect in people who are predisposed to develop diabetes
02:22:52.920
Now, first-phase insulin secretion, strictly speaking, can only be measured with the hyperglycemic clamp
02:23:00.560
So when I acutely raise the glucose from, say, 90 and I raise it to 200, in the first 10 minutes,
02:23:09.720
That is typically lost in people who are going to develop type 2 diabetes.
02:23:13.920
And its counterpart during the OGTT is the insulin level at 30 minutes.
02:23:20.220
So when you ingest the glucose, of course, the rise in glucose is more gentle.
02:23:24.140
So when I acutely raise your glucose from 90 to 200, that big spike of glucose gives the
02:23:31.180
But a low insulin response in the first 30 minutes is another predictor of who's going
02:23:38.160
We use the following numbers in our practice as what we consider what we want to see.
02:23:45.220
At time zero, we want to see you less than 90 and less than 6.
02:23:49.080
At time 30 minutes, we want to see you less than 140 and less than 40.
02:23:53.420
At time 60 minutes, we want to see you less than 130.
02:23:57.960
90 minutes, we want to see you less than 110 and less than 20.
02:24:04.920
But for sure, if they meet those numbers, you're probably safe.
02:24:09.740
Ralph, I don't know where the time went today, but it went.
02:24:18.800
It's interesting because someone listening to this podcast who heard the podcast with
02:24:24.580
Jerry Shulman from probably three years ago will be pleased because the overlap is virtually
02:24:31.440
I mean, that's what's amazing about a topic as rich as this, is you can talk to two of the
02:24:36.080
world's experts and have two completely different conversations.
02:24:40.340
The conversation with Jerry focused so much on the pathophysiology of insulin resistance.
02:24:45.800
Here, we focused much more on the actual organ-specific aspect of type 2 diabetes.
02:24:52.300
We got a masterclass in the pharmacology of it.
02:24:55.680
And then I think kind of brought it back to ways to diagnose it if you're slumming it with
02:25:00.700
those of us in the clinic who don't have clamps.
02:25:03.060
So maybe we should, in the future, we do one with both Jerry and I.
02:25:05.920
I will 100% agree that in a few years, we come back and we do a double version of this
02:25:16.380
Not just obviously for this, but for your contribution to this field.
02:25:22.100
Thank you for listening to this week's episode of The Drive.
02:25:25.360
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