Thomas Buchanan

Thomas Buchanan, M.D., is a University Professor of Medicine, Obstetrics and Gynecology, and Physiology and Biophysics at the Keck School of Medicine of the University of Southern California (USC). He holds the positions of Vice Dean for Research, Chief of the Division of Endocrinology and Diabetes in the Department of Medicine, and founding director of the Southern California Clinical and Translational Science Institute (SC CTSI). He also co-directs the Diabetes and Obesity Research Institute and holds the Bernard J. Hanley Chair in Medicine. Buchanan earned his medical degree from the University of Iowa College of Medicine, completed his residency in internal medicine at the University of Iowa and Good Samaritan Hospital in Phoenix, and undertook fellowship training in endocrinology and metabolism at Northwestern University Medical School in Chicago.

His research specializes in the etiology, pathogenesis, genetics, and prevention of gestational diabetes and type 2 diabetes, focusing on Hispanic Americans. Buchanan and his team have conducted longitudinal studies on high-risk individuals, delineating changes in insulin resistance and secretion that precipitate type 2 diabetes. They led the first successful U.S. type 2 diabetes prevention study, identifying heritable pancreatic beta-cell defects that underpin genetic investigations into metabolic abnormalities predisposing to diabetes. These efforts have significantly advanced clinical management of gestational diabetes and prevention strategies for type 2 diabetes in Hispanic populations. Key publications include "What Is Gestational Diabetes-Really?" (Diabetes, 2025), "Genetic drivers of heterogeneity in type 2 diabetes pathophysiology" (Nature, 2024), "Genome-wide association study and functional characterization identifies candidate genes for insulin-stimulated glucose uptake" (Nature Genetics, 2023), and "Associations among prenatal exposure to gestational diabetes mellitus, brain structure, and child adiposity markers" (Obesity, 2023). Administratively, he directed USC's General Clinical Research Center from 1996 to 2010 and has led the SC CTSI since 2010, securing a $56.8 million NIH Clinical and Translational Science Award and over $180 million in total extramural funding. Buchanan has received numerous accolades, including the USC Associates Award for Creativity in Research (2017), the Mayo H. Soley Award (2014), the American Diabetes Association's Norbert Freinkel Award (1999) and Distinguished Clinical Scientist Award (2004), and election to the Association of American Physicians (2006).

Professional Email: buchanan@usc.edu