Malin, Steven K2; Solomon, Thomas4; Blaszczak, Alecia2; Finnegan, Stephen2; Filion, Julianne2; Kirwan, John P2
1 Section of Cellular and Metabolic Research, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet2 unknown3 Graduate School of Health and Medical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet4 Graduate School of Health and Medical Sciences, Faculty of Health and Medical Sciences, Københavns Universitet
While some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic beta-cell function is unknown. Thirty-five older, obese adults with prediabetes underwent a progressive 12-week supervised exercise intervention (5d/wk for 60min at ~85% HRmax). Insulin and C-peptide (n=23) responses to an OGTT were used to define the first and second phase disposition index (DI; beta-cell function = glucose-stimulated insulin secretion x clamp-derived insulin sensitivity). Maximum oxygen consumption (VO2max) and body composition (dual-energy x-ray absorptiometry and computed tomography) were also measured before and after the intervention. Exercise dose was computed using VO2-heart rate derived linear-regression equations. Subjects expended 474.5±8.8 kcal/session (2372.5±44.1 kcal/week) during the intervention, and lost ~8% body weight. Exercise increased first and second phase DI (P2000 kcal/week) are necessary to enhance beta-cell function in adults with poor insulin secretion capacity.
A J P: Endocrinology and Metabolism (online), 2013, Vol 395, Issue 5
Clinical Trial; Journal Article; Research Support, N.I.H., Extramural; Adult; Aged; Exercise; Female; Humans; Insulin-Secreting Cells; Linear Models; Male; Middle Aged; Oxygen Consumption; Physical Education and Training; Prediabetic State; Time Factors; Weight Loss