Weight Loss in Combination With Physical Activity Improves Endothelial Dysfunction in Human Obesity

Abstract

OBJECTIVE—To test whether weight loss may improve endothelial dysfunction in human obesity, we recruited 28 healthy obese subjects, aged 30–46 years, with BMI 30–43 kg/m2. RESEARCH DESIGN AND METHODS—Endothelium-dependent and -independent vasodilation were investigated by intra-arterial infusion of increasing doses of acetylcholine (ACh; 7.5, 15, and 30 μg · ml−1 · min−1) and sodium nitroprusside (0.8, 1.6, and 3.2 μg · ml−1 · min−1). Insulin resistance was estimated by homeostasis model assessment (HOMA). Weight loss was obtained by caloric restriction and physical activity. RESULTS—We observed a significant reduction in BMI (from 33.1 ± 4.2 to 27.5 ± 4.5 kg/m2, −16.9%, P < 0.0001) and in waist circumference (from 108.2 ± 12.1 to 96.8 ± 12.9 cm, −10.5%, P < 0.0001). Weight loss was also associated with a significant increase in ACh-stimulated forearm blood flow (FBF), from 7.4 ± 2.8 to 12.9 ± 3.4 ml · 100 ml−1 of tissue · min−1 kg/m2 (P < 0.0001). Multivariate regression analysis demonstrated that the only independent predictor of FBF was HOMA, accounting for 44.5% of the variation, whereas the addition of BMI explained another 2.3% of the variation. CONCLUSIONS—Our data demonstrate that energy-restricted diet associated with physical activity induce a significant and clinically relevant improvement in ACh-stimulated vasodilation in obese healthy subjects.