Endothelial dysfunction and type 2 diabetes Part 1: physiology and methodsfor exploring the endothelial function

Coronary artery, cerebrovascular and peripheral vascular disease, are the p rincipal causes of morbidity and mortality in type 2 diabetes mellitus. The accelerated macrovascular disease in type 2 diabetes mellitus is due partl y to the increased incidence of cardiovascular risk factors, such as hypert ension, obesity and dyslipidemia. Advanced glycation and products, glycoxid ised and oxidized low-density lipoproteins and reactive oxygen species link ed to hyperglycemia have all been identified in type 2 diabetes mellitus an d could accelerate macroangiopathy. Hence, the resistance to insulin is an additional independent risk factor, in association with oxidant stress, dys lipidemias, and prothrombic/hypofibrinolytic states. The endothelium is a major organ involved by cardiovascular risk factors, s uch as hypercholesterolemia, hypertension, inflammation, ageing, postmenopa usal status, and smoking. Changes in endothelium function may lead to the c oronary artery circulation being unable to cope with the increased metaboli sm of myocardial muscle independently of a reduced coronary artery diameter . The way endothelial function is altered in diabetic patients is not yet f ully understood, but the loss of normal endothelial function could be invol ved in the pathogenesis of diabetic angiopathy, as endothelial dysfuntion i s associated with diabetic microangiopathy and macroangiopathy. Finally, re cent reports indicate that an improved metabolic control in diabetic patien ts, whatever the treatment used, is associated with near normalization or r estoration of normal endothelial function.