NOS3 and endothelial dysfunction: Reduced plasma adiponectin promotes the synthesis of arginase, an enzyme in the vasculature that inhibits the production of NO by competing with eNOS for the substrate L-arginine15, 16, thereby leading to endothelial dysfunction which is an early predictor of cardiovascular diseases.27 Additionally, asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of eNOS18 and is increased in conditions associated with endothelial dysfunction such as dyslipidaemia, 19 insulin resistance,20 diabetes mellitus,21 and hypertension22, 23.