Concurrent reductions of serum leptin and lipids during weight loss in obese men with type II diabetes

The aim of the study was to examine the effects of weight reduction by exer cise and diet on metabolic control in obese subjects with insulin resistanc e, particularly investigating if changes in serum leptin concentrations wer e directly associated with improvements in metabolic control. Twenty obese men (48 +/- 8 yr; body mass index 32.1 +/- 3.9 kg/m(2)) with previously dia gnosed type II diabetes mellitus were assigned to a 4-wk intervention progr am of exercise (2,200 kcal/wk) and diet (1,000 kcal/day; 50% carbohydrates, 25% protein, 25% fat; polyunsaturated-to-saturated fatty acid ratio 1.0). Intervention induced significant reductions in body weight and serum leptin levels, and improvements in lipoprotein profile and glucose control. Reduc tions in leptin levels were directly associated with reductions in serum tr iglycerides and cholesterol, a finding that was independent of improvements in glucose control. These data show that serum leptin concentrations can b e reduced with caloric restriction and exercise in male patients with type II diabetes, and they suggest a direct relationship between leptin and lipo protein metabolism that is not solely due to weight reduction.