Thursday, September 19, 2024 | New York Academy of Medicine (NYAM)
1216 5th Ave, New York, NY 10029
Dr. Susan K. Fried, PhD, discusses the significant role of sex and race differences in visceral fat and cardiovascular disease. She highlights that men generally have more visceral fat than women, which increases cardiometabolic risk. Additionally, she emphasizes that genetic factors and fat distribution patterns vary by race, influencing the risk of type 2 diabetes and cardiovascular disease. Understanding these differences is crucial for improving health outcomes and disease prediction.
Watch Dr. Dr. Susan K. Fried's Presentation Below:
See Dr. Susan K. Fried's Slides Below:
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Transcript of Dr. Susan K. Fried's Presentation:
[Susan Fried] [0.80s] I would like to thank the organizers for the opportunity to talk to a a good diverse group of clinicians.
[Susan Fried] [8.64s] And, what what David actually asked me to focus on is the role of sex and race differences in visceral fat and cardiovascular disease.
[Susan Fried] [20.71s] I push a green button.
[Susan Fried] [23.59s] Big big green button.
[Susan Fried] [26.63s] I I found it.
[Susan Fried] [29.04s] So I think it's important to point out that, as the previous speaker did as well, that there are different obesity types and not surprisingly, they are different in men and women.
[Susan Fried] [41.95s] I think it's important to remember that, women can be either with most of their fat in the upper body or most of their fat in the lower body.
[Susan Fried] [55.76s] Approximately half the women in the world have an upper body obesity predominantly or even upper body fat distribution.
[Susan Fried] [63.83s] I shouldn't even say obesity.
[Susan Fried] [65.83s] And the other half have a lower body fat distribution.
[Susan Fried] [69.59s] Men also have surprisingly, there do exist male pairs, but, on average, men have less fat in their in their thighs and below the waist.
[Susan Fried] [85.17s] This is not a matter of cosmetics.
[Susan Fried] [87.89s] This has a very clear, biological consequences that we sort of heard.
[Susan Fried] [94.85s] The question that I've been asked to address is whether it's race dependent and whether it's sex dependent.
[Susan Fried] [101.14s] The answer to both those questions is yes, and it has major effects and influences, prediction of cardiometabolic health.
[Susan Fried] [113.58s] So, just a very basic thing.
[Susan Fried] [115.74s] I actually had to go back to an old study from Jean Pierre Dupre, who did a cross sectional study of healthy young individuals, and looked at the amount of visceral adipose tissue, which is on the y axis against, he he did it against subcutaneous adipose tissue, which I'll point out is 8085%, sometimes 90% of the total fat in the body.
[Susan Fried] [143.50s] So it's obvious that the men in the blue have more, visceral fat for a given amount of total adiposity or a total sat.
[Susan Fried] [154.04s] And the most important thing to remember here has been said over and over is that, greater visceral adiposity, identifies more cardiac you know, more cardiometabolic risk even in normal weight, normal non obese, apparently healthy subjects by by standard clinical criteria.
[Susan Fried] [176.18s] And, I think it's also important to point out that men compared to women have more not only more visceral fat, but more epicardial and, and, and, pericardial fat.
[Susan Fried] [193.75s] So why is this important?
[Susan Fried] [196.06s] There have been prospective studies.
[Susan Fried] [198.47s] The odds for a man or a woman developing type 2 diabetes is twice as high in proportion to a larger waist, if they have a larger waist.
[Susan Fried] [210.08s] It's literally lower, attenuated by having more fat in the lower part of the body, in the hips and thighs, so the gluteal and and the thigh fat, which is intriguing, mechanistic question.
[Susan Fried] [225.82s] It's also, important to point out obviously to this audience that peripheral adiposity is protective as well for future metabolic and cardiovascular disease.
[Susan Fried] [237.90s] As you can see in the study, it's the odds of, of becoming, getting developing cardiovascular disease.
[Susan Fried] [245.25s] Again, lower body fat productive, upper body fat, accentuates risk.
[Susan Fried] [253.00s] And finally, the one endpoint that I think we can all agree on how to diagnose, which is death.
[Susan Fried] [259.68s] And, again, I am a basic scientist, but I know that.
[Susan Fried] [264.64s] So, a waist circumference is positively correlated in both sexes, and, this is attenuated by those the the right the right most two graphs with a, a higher waist hip ratio and the so it's important to remember that this occurs after adjustment for BMI.
[Susan Fried] [287.89s] So it's independent of BMI.
[Susan Fried] [290.13s] And what appears to be a normal weight, normal BMI person, you still have this influence of body fat distribution on, on health and and and lifespan.
[Susan Fried] [302.40s] It's also important to realize that there are genetic determinants of this.
[Susan Fried] [306.96s] There are genetic determinants of leg fat, fat in different parts of the body.
[Susan Fried] [311.61s] Literally every depot is developmentally distinct.
[Susan Fried] [315.77s] They have different gene profiles, and they are functionally distinct, both for the secretory function of fat and for the metabolic role of fat.
[Susan Fried] [324.37s] So, again, in this study, there is a race difference.
[Susan Fried] [330.53s] The risk of type 2 diabetes among Hispanic Americans, may clearly has a genetic basis and it's related to the inability to store fat in the lower body, in the thighs, and and the gluteus, actually.
[Susan Fried] [345.75s] So that's very interesting, and that does vary by, by ethnicity and and race.
[Susan Fried] [352.79s] That it's the the bar on the, right are the Hispanic, participants and adjusted for everything and its mother, it still exists.
[Susan Fried] [363.38s] So this is I I just thought I I put this slide in.
[Susan Fried] [367.21s] It's a study that looked at fat distribution in individuals of different races from many different countries across the world, from Arab people, Mexican, Asian, black Americans, Hispanic Americans, Caucasians from different parts of the world.
[Susan Fried] [387.06s] And you can see from what, what what is plotted here, which is leftmost shape is is arm then legs then trunk.
[Susan Fried] [398.11s] And it's sort of very obvious what just essentially a violin plot, is that this varies by, by, by race.
[Susan Fried] [412.06s] So is there a race difference?
[Susan Fried] [416.38s] I must say many years ago, we undertook comparisons of black compared to white individuals, at what's now is, Mount Sinai Morningside.
[Susan Fried] [429.41s] It was Columbia then.
[Susan Fried] [431.89s] And, black women have less visceral fat for the same waist to hip or shake.
[Susan Fried] [437.78s] Less, yet they are at higher risk.
[Susan Fried] [440.65s] That means, obviously, that race matters and it it and race is an independent predictor.
[Susan Fried] [447.54s] It it varies by by, by by the race effect is there independent of of body fat distribution.
[Susan Fried] [458.13s] There are also sex differences, which in in insulin resistance, which we measured directly.
[Susan Fried] [465.29s] And if there are studies that say there are also sex differences, the bottom right graph shows that men are less insulin sensitive to the most important action of insulin, which is to inhibit lipolysis.
[Susan Fried] [477.82s] As you inhibit lipolysis, you don't have excess fatty acids going to other tissues in the body, which is illustrated on this slide, which is very hard to describe without pointing to it, but I will do my best.
[Susan Fried] [490.55s] The upper left hand person has a lot of visceral fat despite his general leanness.
[Susan Fried] [497.82s] That visceral fat drains into the portal vein both fatty acid and and adipicants, ions, which are hormones and anything else released from, adipose tissue goes directly to the liver.
[Susan Fried] [511.32s] Not amazingly, this is related to hepatosteatosis.
[Susan Fried] [515.32s] It goes to skeletal muscle, the vasculature, kidneys, and and heart.
[Susan Fried] [519.45s] In heart, we also have a very local effect.
[Susan Fried] [522.25s] In contrast, the other abdominal fat in terms of, flux of fatty acids is the greatest flux to the systemic circulation, which is distributed then to all the other organs in the body.
[Susan Fried] [535.96s] And on a weight basis, gluteal femoral fat is less.
[Susan Fried] [539.08s] It has less of an effect.
[Susan Fried] [541.48s] Combined, if you if if if your fat distribution is different, this is why you get ectopic fat distribution as was pointed out both within and between, fibers of skeletal muscle.
[Susan Fried] [556.93s] So and you also have very clear effects in the heart.
[Susan Fried] [560.69s] Apparently, on, on CT scans, like, you can see the fibrosis in fat, in in dysfunctional fat.
[Susan Fried] [568.85s] You can see different qualities of the density of fat, which means that we can get more refined in how we diagnose.
[Susan Fried] [579.18s] Thank you very much for your attention.
The presentations were hosted by I-ELCAP – The International Early Lung Cancer Action Program.
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