Weight loss is associated with improved endothelial dysfunction via NOX2-generated oxidative stress down-regulation in patients with the metabolic syndrome

The aim of this study was to assess whether adherence to a restricted-calorie, Mediterranean-type diet improves endothelial dysfunction and markers of oxidative stress in patients with metabolic syndrome. A moderately low-calorie (600 calories/day negative energy balance), low-fat, high-carbohydrate diet ( or < 5% after 6 months. Group A (n = 23) showed a remarkable decrease in body weight (-6. 8%), body-mass-index (-4. 6%), waist circumference (-4. 8%), HOMA-IR (-27. 2%), plasma glucose, glycosylated haemoglobin, total and LDL-cholesterol, blood pressure, serum NOX2 (the catalytic core of NADPH oxidase) (-22. 2%) and urinary8-isoprostanes (-39. 0%) and an increase of serum NOx (Nitrite/Nitrate) (+116. 8%) and adiponectine (+125. 5%) as compared with those in group B (n = 30). A statistically significant increase in brachial artery flow-mediated dilatation was observed in group A (+24. 7%; p < 0. 001), while no changes were present in group B. Variations of flow-mediated dilatation were statistically and negatively correlated with changes of serum NOX2 levels (p = 0. 04), body-mass-index (p < 0. 01), waist circumference (0. 01), glycosylated haemoglobin (p < 0. 01), LDL-cholesterol (p < 0. 01) and triglycerides (p < 0. 05) and positively correlated with changes of serum NOx (p < 0. 001) and adiponectin (p = 0. 01). The results show that moderate weight loss is able to improve endothelial dysfunction in patients with the metabolic syndrome. The coexistent decrease of NOX2 activation suggests a role for oxidative stress in eliciting artery dysfunction. © 2011 SIMI