Resting leptin responses to acute and chronic resistance training in type 2 diabetic men and women

PURPOSE: To evaluate the plasma leptin levels similar to 24 h post-exercise in control and type 2 diabetic subjects and to establish if observed chang es in leptin concentrations were acute or chronic effects of a resistance t raining program. METHODS: Thirty men and women (17 controls and 13 type 2, obese diabetics, age 40-55y) had resting blood samples drawn at 08:00 h (12 h postprandial) at the beginning of the study (pre-training), 24 h after a three repetition maximal weight lifting bout (acute) and 72 h after their last training bou t of 6 weeks of resistance training (chronic). The two groups were not matc hed with respect to body mass index and the control subjects were not norma l weight. Subjects weight-trained three times a week, for 6 weeks, for I h, training both the upper and lower body. RESULTS: Serum leptin concentrations were significantly higher in the type 2 diabetics than in the control group at pre-training (41.4 +/- 8.9 vs 11.4 +/- 3.0 ng/ml, P < 0.05, respectively). Compared to pre-training, the lept in levels decreased significantly (P < 0.01) after acute exercise in the di abetics but not in the control subjects (diabetics 30.9 +/- 7.1 vs controls 10.6 +/- 2.6 ng/ml). Approximately 72 h after 6 weeks of exercise training , the leptin concentrations were no longer lower than the pre-training valu es in either group (36.9 +/- 8.8 vs 11.9 +/- 8.8 ng/ml, respectively, P = N S). When leptin concentrations were log transformed and adjusted for fat ma ss there were still significant changes in leptin levels over time and betw een the control and diabetic group (P < 0.05). CONCLUSIONS: The type 2 diabetics showed a significant 30% reduction in res ting leptin levels 24 h after a single bout of resistance exercise. This wa s an acute response to resistance exercise and not a chronic training effec t (no difference between pre-training and chronic). The decreased resting l eptin concentrations similar to 24h post-acute exercise may be due to reduc ed glucose availability to the adipose tissue, particularly in the diabetic subjects. There is no chronic effect of resistance exercise on leptin conc entrations.