Richard N. Bergman , PhD

Research Interests

Dr. Bergman is Chair of the Keck School of Medicine Physiology/Biophysics Department, and is Director of the Clifton Stewart Laboratories. Our research group studies diabetes and obesity. Type 2 diabetes is disease which afflicts 21,000,000 Americans, and which is a primary cause of heart disease, blindness, and kidney disease. Thus, if we could cure or prevent NIDDM, we would do much to improve the overall health of the U.S. population. Obesity, which is increasing at a rapid rate in the United States and worldwide is a primary risk factor for Type 2 diabetes. Because this form of diabetes is particularly prevalent in minority communities, i.e., the Hispanic and African-American populations, it is particularly important that we study its causes and cures in the Los Angeles area, which is one of the most multicultural cities in the world.

Dr. Bergman and his colleagues include approximately 25 individuals, including 4 faculty, and associated scientists at various levels of accomplishment (postdoctoral level and graduate students), and highly qualified technical and administrative personnel. These individuals are working on many different projects, ranging from cell biology to systems and integrative biology, as well as population genetics. All projects relate ultimately to diabetes research. Our work is supported the National Institutes of Health, by the American Diabetes Association, and industry. Primary projects are described as follows.

We have a long history of combining mathematical modeling with physiological and pathophysiological mechanisms. Our laboratory pioneered the “minimal model” approach to assessment of metabolic function. The model allows for the quantification of specific physiological functions which may be abnormal and increase risk for diabetes. We proposed the “hyperbolic law of glucose tolerance,” which posits that there is a specific quantitative relationship between insulin secretion and insulin action, such that insulin resistance causes a compensatory upregulation of insulin response, and the product of insulin secretion x insulin action = constant. The name of this constant is the “disposition index,” and it is the most accurate measure of beta-cell function in the human body. The index has been important in epidemiological and human genetic studies. In fact, the disposition index is the most powerful predictor of Type 2 diabetes. Also, genome-wide association studies have revealed that the known genetic variants associated with diabetes risk appear to code for aspects of pancreatic beta-cell function, and several of these variants are related to the disposition index. Thus, in our laboratory, modeling associated with physiological validation has led to increased understanding of epidemiologic and genetic causes of Type 2 diabetes. With this understanding we have examined the mechanisms by which a variety of molecules which can alter diabetes risk. These include antipsychotics, cannabinoid antagonists, and GLP-1 analogs.

We are examining the mechanisms responsible for the upregulation of beta-cell function in the face of insulin resistance. One possible mediator of this upregulation is the group of lipid molecules known as “fatty acids.” It is known that fat in the “belly” – that is the visceral compartment – is particularly deleterious to metabolic function. We have hypothesized that release of free fatty acids (FFA) from this compartment – driven by the sympathetic nervous system – is responsible for insulin resistance due to visceral fat. We reported that FFA levels are particularly high in the middle of the night (3 AM) and we are testing the concept that a nocturnal surge in FFA is responsible for the insulin resistance associated with visceral fat (the so-called “metabolic syndrome”).

Our laboratory has been honored recently with several important scientific prizes for our work, including the Banting Medal given by the American Diabetes Association, and the Naomi Berrie Award given by Columbia University. We always welcome new junior scientists and students into our research group.

For further information please click here.

Degrees

University of Pittsburgh, PHD, 1971