Adiponectin: possible link between metabolic stress and oxidative stress in the elderly.

Abstract

The aim of this study was to evaluate the relationships between the serum levels of adiponectin and systemic oxidative stress exerted on lipids, proteins, as well as endothelial function and cardiovascular diseases (CVD) risk markers, in elderly subjects with metabolic syndrome (MS). The serum advanced glycation and oxidation protein products, low-density lipoprotein susceptibility to oxidation (oxLDL), nitric oxide metabolic pathway products (NOx), serum lipid peroxidation, as well as total antioxidant/oxidative capacity (TAC/TOC), were analyzed in elderly subjects with MS (n=44), compared to aged-matched control (n=39). We pointed out significantly lower levels of adiponectin in elderly MS subjects concomitantly with significantly higher levels of oxidative stress and CVD risk markers. Significant positive correlations were found between serum adiponectin levels and HDL-cholesterol (p<0.05) and the total cholesterol/LDL-cholesterol ratio (p<0.01). Additionally, adiponectin levels were significantly inversely associated with insulin resistance index (HOMA-IR, r=-0.348; p<0.05) and serum lipid peroxidation (r=-0.337; p<0.05), and significantly positively with the antioxidant capacity (TAC, r=0.339; p<0.05). Conversely, adiponectin levels were significantly negatively (r=-0.310; p<0.05) associated with serum uric acid concentration. The major protective role of adiponectin versus stress related to an impaired glucose and lipid metabolism suggests that adiponectin plays a critical role in adiposity-related metabolic stress and redox homeostasis.