A Randomized Controlled Trial of Resistance Exercise Training to Improve Glycemic Control in Older Adults With Type 2 Diabetes

A Randomized Controlled Trial of Resistance Exercise Training to Improve Glycemic Control in Older Adults With Type 2 Diabetes Carmen Castaneda , MD, PHD , Jennifer E. Layne , MS , Leda Munoz-Orians , BS , Patricia L. Gordon , RN, PHD , Joseph Walsmith , MA , Mona Foldvari , MS , Ronenn Roubenoff , MD, MHS , Katherine L. Tucker , PHD and Miriam E. Nelson , PHD Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts Abstract OBJECTIVE —To determine the efficacy of high-intensity progressive resistance training (PRT) on glycemic control in older adults with type 2 diabetes. RESEARCH DESIGN AND METHODS —We performed a 16-week randomized controlled trial in 62 Latino older adults (40 women and 22 men; mean ± SE age 66 ± 8 years) with type 2 diabetes randomly assigned to supervised PRT or a control group. Glycemic control, metabolic syndrome abnormalities, body composition, and muscle glycogen stores were determined before and after the intervention. RESULTS —Sixteen weeks of PRT (three times per week) resulted in reduced plasma glycosylated hemoglobin levels (from 8.7 ± 0.3 to 7.6 ± 0.2%), increased muscle glycogen stores (from 60.3 ± 3.9 to 79.1 ± 5.0 mmol glucose/kg muscle), and reduced the dose of prescribed diabetes medication in 72% of exercisers compared with the control group, P = 0.004–0.05. Control subjects showed no change in glycosylated hemoglobin, a reduction in muscle glycogen (from 61.4 ± 7.7 to 47.2 ± 6.7 mmol glucose/kg muscle), and a 42% increase in diabetes medications. PRT subjects versus control subjects also increased lean mass (+1.2 ± 0.2 vs. −0.1 ± 0.1 kg), reduced systolic blood pressure (–9.7 ± 1.6 vs. +7.7 ± 1.9 mmHg), and decreased trunk fat mass (−0.7 ± 0.1 vs. +0.8 ± 0.1 kg; P = 0.01–0.05). CONCLUSIONS —PRT as an adjunct to standard of care is feasible and effective in improving glycemic control and some of the abnormalities associated with the metabolic syndrome among high-risk older adults with type 2 diabetes. 1RM, one-repetition maximum testing CV, coefficient of variation HNRCA, Human Nutrition Research Center on Aging NHANES, the Third National Health and Nutrition Examination Survey PASE, Physical Activity Scale for the Elderly PRT, progressive resistance training Footnotes Address correspondence and reprint requests to Carmen Castaneda, MD, PhD, Tufts University, 711 Washington St., Boston, MA 02111. E-mail: ccastaneda{at}hnrc.tufts.edu . Received for publ