Mobilization of visceral adipose tissue related to the improvement in insulin sensitivity in response to physical training in NIDDM - Effects of branched-chain amino acid supplements

OBJECTIVE - To evaluate the effects of an intense physical training program on abdominal fat distribution, glycemic control, and insulin sensitivity in patients with NIDDM and to determine whether branched-chain amino acid (BCAA) supplements influence these effects. RESEARCH DESIGN AND METHODS - Twenty-four patients (ages 45 +/- 2 [mean +/- SE] years, BMI 30.2 +/- 0.9 kg/m(2) HbA(1c) 7.9 +/- 0.3%) were randomly assigned to four groups: training plus BCAA supplement (n = 6), training plus placebo (n = 6), sedentary plus BCAA supplement (n = 6), and sedentary plus placebo (n = 6). Physical training consisted of a supervised 45-min cycling exercise at 75% of their oxygen uptake peak (Vo(2) peak) two times per week and an intermittent exercise one time per week for 2 months. RESULTS - Patients who exercised increased their Vo(2) peak by 41% and their insulin sensitivity by 46%. Physical training significantly decreased abdominal fat evaluated by magnetic resonance imaging (umbilicus), with a greater loss of visceral adipose tissue (VAT) (48%) in comparison with the loss of subcutaneous adipose tissue (18%), but did not significantly affect body weight. The change in visceral abdominal fat was associated with the improvement in insulin sensitivity (r = 0.84, P = 0.001). BCAA supplementation had no effect on abdominal fat and glucose metabolism. CONCLUSIONS - Physical training resulted in an improvement in insulin sensitivity with concomitant loss of VAT and should be included in the treatment program for patients with NIDDM.