Transcript
A (0:02)
Welcome to this special edition of Diabetes Core Update, where we'll discuss diabetes and hypercortisolism. You may be asking yourself, why are we discussing hypercortisolism? It is vanishingly rare. We're going to share with you some new evidence showing that in people with uncontrolled diabetes, the prevalence may be approximately 24%. This is really exciting, important new information. I'm your host, Dr. Neal Skolnick, professor of Family and Community Medicine at the Sidney Kimmel Medical College of Thomas Jefferson University. And this special series of Diabetes Core Update is sponsored by corcept. Joining us for today's episode, we are really privileged to have Dr. John Buce. Dr. Buce is the Vern S. Cavanis Distinguished professor and Director of the Diabetes center at the University of North Carolina Chapel Hill School of Medicine. He has been President for Medicine and Science at the American Diabetes association, is a recipient of the ADA Outstanding Achievement in Clinical Diabetes Research Award, has authored more than 500 publications and participated and led numerous clinical trials. Welcome, John.
B (1:23)
It's a pleasure.
A (1:25)
John, let's just jump in and start with the basics. What is hypercortisilism and can you distinguish that for us from classic Cushing's syndrome?
B (1:35)
Yeah, so it's a spectrum. Hypercortisol technically means too much cortisol in the blood. How would you end up detecting that? There's a variety of different tests. What we learned about in medical school was Cushing's syndrome, which is the presence of hypercortisolism with other features. And so the things that make the syndrome are things like dorsal cervical fat pad or quote, buffalo hump cloth or moon facies or purple stria on the abdomen, often associated with hypertension, diabetes, osteoporosis. People die young with Cushing full blown Cushing syndrome if it can't be controlled due to cardiovascular disease. But what we're talking about here is hypercortisolism. Really? Without Cushing syndrome, the classic cause is a pituitary tumor that makes excess ACTH and drives cortisol production. That's Cushing's disease. But here, what we're talking about is hypercortisolism by itself.
A (2:48)
Yeah. And the Cushing's syndrome is rare. I've been in practice over 30 years. I do not think I have very often seen it. But hypercortisolism, as we'll learn, is kind of lurking out there a lot more commonly. Let's now talk a little bit about pathophysiology and why this would be important. So how does cortisol Affect glucose control?
B (3:13)
Well, mechanistically, there are many different pathways that cortisol affects relevant to glucose metabolism. So first, it has an effect in the islet to reduce insulin secretion, it has effect in muscle and fat to reduce insulin action or cause insulin resistance. In the liver, it causes excess hepatic glucose production. So that's a major cause of fasting hyperglycemia and increases the production of lipoproteins from de novo lipogenesis. So it promotes hypertriglyceridemia. It affects the GLP1 system as well, the production of GLP1. So it has vitamin very broad effects that all contribute potentially to hyperglycemia. And many people with full blown Cushing's syndrome do have diabetes as a consequence. So it can be a secondary cause of diabetes.
