Plasma Adiponectin is not Altered by Moderate or Heavy Aerobic Exercise Training in Elderly, Overweight Individuals

Abstract

PURPOSE: To examine the influence of moderate-intensity (50% of VO2 peak) exercise training (MI) versus high-intensity (75% of VO2 peak) exercise training (HI) on plasma adiponectin in elderly, overweight individuals. METHODS: Following complete medical and physical exams, 18 overweight (BMI=29±1 kg/m2) elderly (74±1 y) subjects were randomized to 1) HI, 2) MI, or a non-exercising control group (CON). Subjects enrolled in HI or MI completed a 12 week exercise training protocol designed to expend 1000 kcal/week. Body composition testing was completed prior to and immediately following the exercise training intervention using dual energy x-ray absorptiometry. Plasma adiponectin was measured by ELISA, and the enzyme activity was determined spectrophotometrically by increased absorbance at 450 nm – 590nm. RESULTS: As expected, there was no change in VO2peak in CON, while VO2peak was significantly improved in HI and MI. There was no significant change in body weight or BMI, and % fat did not change from pre- to post-intervention in MI, HI or CON. In terms of plasma adiponectin, there was no change in MI (A of 1.1±2.1 ng/ml), HI (A of 0.9±2.1 ng/ml) or CON (A of 1.2±1.3 ng/ml). CONCLUSION: We have previously shown that exercise training-induced improvements in glucose metabolism that occur without weight loss are completely reliant on changes in non-oxidative glucose disposal. In addition, we have now demonstrated that aerobic exercise training intensity independent of weight loss does not influence plasma adiponectin levels, and therefore does not play a plausible role in the improvement of glucose metabolism under such conditions. Supported by NIH grants KO1 DK 64716–01 (RHC), F32AG21374 (NPH), and RO1 AG 19346–01 (WJE) and AHA grant SDA 0335172N (rHC).