Reduced leptin and resistin and increased adiponectin are associated with improved endothelial function during weight loss with low fat compared to low carbohydrate diets

Abstract

Previously we showed that low fat (LF) diets improved endothelium‐dependent flow mediated dilation (FMD) compared to isocaloric low carbohydrate (LC), high fat diets. The purpose of this study was to determine 1) the relationships between pro‐ (leptin and resistin) and anti‐ (adiponectin) atherogenic adipokines on endothelial function during weight loss with LF and LC diets and 2) if exogenous adiponectin improves microvascular endothelial function in subjects on LC diets. Healthy subjects (BMI: 29–39) were assigned to a LF or an isocaloric LC diet for 6 weeks. Brachial artery FMD was determined with ultrasound. Leptin, resistin, and adiponectin were determined with ELISA (baseline and week 6). In separate studies, endothelium‐dependent acetylcholine (ACh) dilations were determined in isolated resistance arteries from subcutaneous fat biopsies. Body weight, fat mass, and waist circumference was reduced in LF and LC groups (P<0.05). Increased FMD on the LF diet was related to increased adiponectin (r=0.55; P=0.04), decreased leptin (r=−0.78;P=0.03), and decreased resistin (r=−0.47;P=0.01). Leptin (but not resistin) was reduced after LC. Exogenous adiponectin (10μg/ml) reversed impaired ACh dilations in isolated resistance arteries of subjects on LC diets. These results suggest that reduced leptin and resistin and increased adiponectin contribute to improved endothelial function during weight loss on LF but not LC diets. Adiponectin may reverse microvascular endothelial dysfunction induced by high fat, LC diets.