RESUMO
PURPOSE: To delineate the direct effect of physical activity on adiponectin metabolism, we investigated the impact of contrasted physical activity changes, independent of body mass changes, on adiponectin plasma concentration and muscle sensitivity in lean and overweight adult males. METHODS: Eleven physically active lean men (70.6 ± 2.1 kg) were subjected to 1-month detraining; 9 sedentary lean men (73.1 ± 3.3 kg); and 11 sedentary overweight men (97.5 ± 3.0 kg) participated in a 2-month aerobic-exercise training program. Diet was controlled to maintain stable energy balance. Body composition, VO2peak, circulating adiponectin, adipose and muscle tissue adiponectin, muscle adiponectin receptors, and APPL1 mRNAs were measured before and after the interventions. RESULTS: At baseline, plasma high-molecular-weight adiponectin concentration was lower in both active lean (5.44 ± 0.58 µg/mL) and sedentary overweight (5.30 ± 1.06 µg/mL) than in sedentary lean participants (7.44 ± 1.06 µg/mL; both p < 0.05). Training reduced total and high-molecular-weight adiponectin concentrations by, respectively, -32 and -42 % in sedentary lean, and -26 and -35 % in sedentary overweight, while detraining increased them by +25 and +27 % in active lean participants. Total and high-molecular-weight adiponectin changes were inversely correlated with VO2peak changes (respectively, R 2 = 0.45, R 2 = 0.59; both p < 0.001) and positively with changes in fasting plasma insulin (both p < 0.05). Muscle and adipose tissue adiponectin mRNA did not differ between groups and with interventions. Muscle AdipoR2 and APPL1 mRNAs were lower in sedentary groups compared with the active group; and were positively associated with VO2peak and inversely with fasting plasma insulin concentration. CONCLUSION: Plasma adiponectin concentration is inversely correlated with aerobic capacity. Future investigations will need to confirm the contribution of changes in muscle adiponectin sensitivity.