Aging Per Se Does Not Influence Glucose Homeostasis

Aging Per Se Does Not Influence Glucose Homeostasis In vivo and in vitro evidence Pascal Imbeault , PHD 1 , Johannes B. Prins , MD, PHD 2 , Manuela Stolic , BSC 2 , Anthony W. Russell , MD 2 , Trisha O’Moore-Sullivan , MD 2 , Jean-Pierre Després , PHD 3 , Claude Bouchard , PHD 4 and Angelo Tremblay , PHD 5 1 School of Human Kinetics, University of Ottawa, Ontario, Canada 2 Department of Diabetes and Endocrinology, Princess Alexandra Hospital, Brisbane, Australia 3 Québec Heart Institute, Laval Hospital Research Center, Ste-Foy, Québec, Canada 4 Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana 5 Division of Kinesiology, Department of Social and Preventive Medicine, Laval University, Ste-Foy, Québec, Canada Abstract OBJECTIVE —To assess the effect of age on glucose metabolism by examining 1 ) glucose metabolism in young and middle-aged subjects when total or regional adiposity is taken into account and 2 ) in vitro glucose transport in adipose tissue explants from young and middle-aged women paired for total and abdominal adiposity. RESEARCH DESIGN AND METHODS —Study 1: body composition, subcutaneous abdominal and visceral adipose tissue areas, and fasting and oral glucose–stimulated glucose and insulin were measured in 84 young and 81 middle-aged men and in 110 young and 91 middle-aged women. Study 2: glucose uptake in subcutaneous abdominal and visceral adipose tissue explants were measured in eight young and eight middle-aged women. RESULTS —Study 1: young and middle-aged men showed similar subcutaneous abdominal tissue area, whereas fat mass and visceral adipose tissue were greater in middle-aged than in young men ( P < 0.01). Fat mass and subcutaneous and visceral adipose tissue areas were greater in middle-aged as compared with young women ( P < 0.01). Fasting plasma glucose and the glucose response to an oral glucose tolerance test were significantly higher in middle-aged than in young men and women ( P < 0.001). Statistical control for visceral adipose tissue area eliminated the difference seen in glucose response in men and women. Study 2: glucose transport in subcutaneous and omental adipose tissue did not differ between young and middle-aged women. CONCLUSIONS — 1 ) Visceral obesity, more than age per se, correlates with glucose intolerance in middle-aged subjects; 2 ) aging does not influence in vitro adipose tissue glucose uptake. AUC, area under the curve CT, computed tomography DMEM, Dulbecco’s modified