Effect of Weight Loss With Lifestyle Intervention on Risk of Diabetes

Effect of Weight Loss With Lifestyle Intervention on Risk of Diabetes Richard F. Hamman , MD, DRPH 1 , Rena R. Wing , PHD 2 , Sharon L. Edelstein , SCM 3 , John M. Lachin , SCD 3 , George A. Bray , MD 4 , Linda Delahanty , MS, RD 5 , Mary Hoskin , MS, RD 6 , Andrea M. Kriska , PHD 7 , Elizabeth J. Mayer-Davis , PHD 8 , Xavier Pi-Sunyer , MD 9 , Judith Regensteiner , PHD 1 , Beth Venditti , PHD 7 , Judith Wylie-Rosett , EDD, RD 10 and for the Diabetes Prevention Program Research Group 1 University of Colorado at Denver and Health Sciences Center, Denver, Colorado 2 Department of Psychiatry and Human Behavior, Brown University, Providence, Rhode Island 3 Biostatistics Center, George Washington University, Washington, DC 4 Pennington Biomedical Research Center, Baton Rouge, Louisiana 5 Diabetes Research Center, Massachusetts General Hospital, Boston, Massachussetts 6 Southwestern Indian Center, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona 7 Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania 8 University of South Carolina School of Public Health, Columbia, South Carolina 9 Roosevelt-St. Luke’s Hospital, New York, New York 10 Albert Einstein College of Medicine, Bronx, New York Address correspondence and reprint requests to Richard F. Hamman, MD, DrPH, Diabetes Prevention Program Coordinating Center, The Biostatistics Center, George Washington University, 6110 Executive Blvd., Suite 750, Rockville, MD 20852. E-mail: dppmail{at}biostat.bsc.gwu.edu Abstract OBJECTIVE —Diabetes Prevention Program (DPP) participants randomized to the intensive lifestyle intervention (ILS) had significantly reduced risk of diabetes compared with placebo participants. We explored the contribution of changes in weight, diet, and physical activity on the risk of developing diabetes among ILS participants. RESEARCH DESIGN AND METHODS —For this study, we analyzed one arm of a randomized trial using Cox proportional hazards regression over 3.2 years of follow-up. RESULTS —A total of 1,079 participants were aged 25–84 years (mean 50.6 years, BMI 33.9 kg/m 2 ). Weight loss was the dominant predictor of reduced diabetes incidence (hazard ratio per 5-kg weight loss 0.42 [95% CI 0.35–0.51]; P < 0.0001). For every kilogram of weight loss, there was a 16% reduction in risk, adjusted for changes in diet and activity. Lower percent of calories from fat and increased physical activity predicted weight loss. Increased physical activity was important to help sustain weight loss. Among 495 participants not meeting the weight loss goal at year 1, those who achieved the physical activity goal had 44% lower diabetes incidence. CONCLUSIONS —Interventions to reduce diabetes risk should primarily target weight reduction. DPP, Diabetes Prevention Program IGR, insulin-to-glucose ratio ILS, intensive lifestyle intervention Footnotes A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted June 5, 2006. Received March 14, 2006. DIABETES CARE