Ralph DeFronzo, M.D.

Dr. Ralph DeFronzo graduated from Yale University with a degree in biology and biochemistry before going on to Harvard Medical School.  Following internal medicine training at Johns Hopkins, he completed fellowships in Endocrinology (NIH, Baltimore City Hospital) and Nephrology (Hospital of the University of Pennsylvania). He holds the Joe R. & Teresa Lozano Long Distinguished Chair in Diabetes in the Long School of Medicine at UT Health San Antonio, where he has been on the faculty since 1988. Dr. DeFronzo is directly responsible for many seminal advances achieved in diabetes over the last 50 years. He was a leader in developing the concept of insulin resistance, the defining characteristic of Type 2 diabetes, resulting in novel ideas about the development and progression of diabetes.

Dr. DeFronzo led the U.S. development of metformin, the first-line medication for treatment of diabetes, and ushered it through FDA approval in 1995. More recently, he discovered a new approach to diabetes treatment that targets glucose reabsorption in the kidneys. This work led to the development and approval of other widely used drugs, including dapagliflozin, empagliflozin, and canagliflozin. His most recent work, along with Dr. Bruno Doiron, has led to a possible cure for type 1 diabetes and is being developed by studies in large animals.

In 1987 Dr. DeFronzo received the Lilly Award from the American Diabetes Association (ADA) as the outstanding young investigator. In 2002 he received the Albert Renold Award from the ADA for the training of more than 200 young diabetes investigators. In 2005 he received the Novartis Award at the Annual Scientific Meeting of the American Diabetes Association as the outstanding clinical investigator worldwide. In 2008 he won the Banting Award from the ADA and the Claude Bernard Award from the European Association for the Study of Diabetes (EASD). The highest scientific awards given by the ADA and EASD.  In 2017, Dr. DeFronzo won the Harold Hamm International Prize for Biomedical Research in Diabetes. He is also the author of over 800 publications in peer review journals and is the editor of the International Textbook of Diabetes Mellitus.

Dr. Ralph DeFronzo's major interests focus on the pathogenesis and treatment of type 2 diabetes mellitus and the central role of insulin resistance in the metabolic-cardiovascular cluster of disorders known collectively as the Insulin Resistance Syndrome. Using the euglycemic insulin clamp technique in combination with radioisotope turnover methodology, limb catheterization, indirect calorimetry, and muscle biopsy, he has helped to define the biochemical and molecular disturbances responsible for insulin resistance in type 2 diabetes mellitus.