Diabetes is a vascular disease: the role of endothelial dysfunction in pathophysiology of cardiovascular disease in diabetes

Diabetes mellitus (DM) is not just a metabolic disorder-it is as much a vascular disease because most patients who have diabetes die of cardiovascular disease (CD) [1-6]. Several studies have shown that cardiovascular complications account for most of the morbidity and mortality that are associated with diabetes and metabolic syndrome (MS) [1-5]. Recent data also showed that at a younger age (<45 years), diabetes was associated with an increased risk of cardiovascular disorders; the presence of diabetes in women takes away the gender protection for coronary heart disease (CHD) in the premenopausal period [2-3]. Several studies have shown the impact of DM on cardiovascular events. Haffner et al [5] prospectively demonstrated that the risk of developing a myocardial infarction (MI) in diabetic patients who had no history of CHD was equivalent to the risk that was observed in nondiabetic survivors who had a previous MI during the 7-year follow-up period. Another recent study showed that in middle-aged men who had MS there was a significant increase in the risk of dying of CHD (even after adjustment for conventional risk factors) [6]. The data from these studies suggest that many patients who have diabetes or MS already may have vascular disease when they are clinically diagnosed with diabetes or MS. Endothelial dysfunction is one of the earliest steps in the process of atherosclerosis and vascular disease. Emerging evidence shows that a variety of pathways can lead to endothelial dysfunction and vascular disease in patients who have diabetes and MS.