Changes in plasma leptin and insulin action with resistive training in postmenopausal XXXX .

@entity1 @entity353 @entity1425 @entity26 @entity4854 @entity2661 @entity1063 @entity1602 @entity413
OBJECTIVE: To determine the effects of 16 weeks of resistive training alone (RT) and with @entity353 (RT+WL) on insulin action, plasma leptin concentrations and leptin's relationship to beta-cell sensitivity to @entity413 , resting metabolic rate (RMR), and plasma @entity2661 in older @entity1 . SUBJECTS: Fifteen obese postmenopausal @entity1 aged 50-69 y. MEASUREMENTS: Body composition (by dual-energy X-ray absorptiometry), RMR (by indirect calorimetry), insulin action (by 2 h @entity1602 clamps; 7.9 mmol/l above basal plasma @entity413 levels), plasma leptin and insulin (by RIA), and plasma @entity2661 (by enzymatic methods). RESULTS: RT and RT+WL resulted in significant improvements in muscular strength (P<0.01) with no changes in maximal @entity26 consumption. Body weight, fat mass and percent body fat did not change with RT, but decreased with RT+WL (P<0.001). Fat-free mass and RMR increased after training when both groups were combined (P<0.05). The insulin response during the last 20 min of the 2 h @entity1602 clamps decreased 16% after RT (P=0.05), 43% after RT+WL (P<0.05), and 29% in the entire group (P<0. 01) without any changes in @entity413 utilization. Plasma leptin levels did not change after RT, but decreased by 36% after RT+WL (P<0.05). Baseline leptin levels correlated with body weight (r=0.68, P<0.01), body fat mass (r=0.77, P<0.001), and RMR (kcal/d; (r=0.69, P<0.005), but not with baseline @entity1063 or @entity1425 levels. Plasma leptin levels correlated with basal insulin (r=0.73, P<0.005), and approached significance with the 0-10 min and 100-120 min insulin response to @entity4854 before training (both r=0.51, P=0.07). In the entire group, the change in insulin response from 100-120 min during the clamp correlated with the change in leptin levels (r=0.60, P<0.05), but this was not independent of changes in fat mass. CONCLUSIONS: Although changes in leptin levels were not related to changes in RMR or plasma @entity2661 after RT with and without @entity353 , the increase in insulin action after training and @entity353 may be related to the decrease in leptin levels that were mediated by the loss of body fat in the obese, postmenopausal @entity1 . International Journal of Obesity (2000)24, 27-32
