RESUMO
OBJECTIVES: The primary aims of the study were to examine the effect of resveratrol on skeletal muscle SIRT1 expression and energy expenditure in subjects with Type 2 diabetes mellitus (T2DM). BACKGROUND: Animal and in vivo studies indicate that resveratrol increases SIRT1 expression that stimulates PGC1α activity. Subsequent upregulation of AMPK and GLUT4 expression are associated with improved insulin sensitivity in peripheral tissues. METHODS: Ten subjects with T2DM were randomized in a double-blind fashion to receive 3g resveratrol or placebo daily for 12 weeks. Secondary outcomes include measures of AMPK, p-AMPK and GLUT4 expression levels, energy expenditure, physical activity levels, distribution of abdominal adipose tissue and skeletal muscle fiber type composition, body weight, HbA1c, plasma lipid subfraction, adiponectin levels, and insulin sensitivity. RESULTS: There was a significant increase in both SIRT1 expression (2.01 vs. 0.86 arbitrary units [AU], p = .016) and p-AMPK to AMPK expression ratio (2.04 vs. 0.79 AU, p = .032) in the resveratrol group compared with the placebo group. Although the percentage of absolute change (8.6 vs. -13.9%, p = .033) and percentage of predicted resting metabolic rate (RMR; 7.8 vs. -13.9%, p = .013) were increased following resveratrol, there was a significant reduction in average daily activity (-38 vs. 43.2%, p = .028) and step counts (-39.5 vs. 11.8%, p = .047) when compared with placebo. CONCLUSIONS: In patients with T2DM, treatment with resveratrol regulates energy expenditure through increased skeletal muscle SIRT1 and AMPK expression. These findings indicate that resveratrol may have beneficial exercise-mimetic effects in patients with T2DM.
