Hypoglycemic pharmacological treatment of type 2 diabetes: targeting the endothelium

Cardiovascular disease is by far the most common complication of type 2 diabetes and also the most serious one. Suffering from type 2 diabetes mellitus not only dramatically increases the risk of cardiovascular disease but is also associated with poor survival, both acutely and in the long term after a myocardial infarction. In fact, total mortality from coronary artery disease in subjects with type 2 diabetes mellitus, without a previous myocardial infarction, is as high as that of non-diabetic individuals with a previous infarction. Intense research efforts have thus been directed towards exploring the reasons for why particularly type 2 diabetic patients have such a poor prognosis suffering from cardiovascular disease. Obesity-related type 2 diabetes ("diabesity"), including the metabolic syndrome, is rapidly rising in prevalence. About 80% of all type 2 diabetes co-exists with insulin resistance. Endothelial dysfunction is a ubiquitous abnormality in insulin-resistant states that might contribute to premature atherosclerosis in a multifactorial and complex way. Low grade inflammation may play a role in development insulin resistance and type 2 diabetes and it has been proposed that atherosclerosis is basically an inflammatory disease. Thus, the pathophysiology of insulin resistance, the metabolic syndrome, and atherosclerosis may share inflammatory basis as a common denominator. Also, insulin resistance is not confined to skeletal muscle, adipose tissue and the liver, but also to the endothelium. Insulin resistance and endothelial dysfunction co-exist, where chronic inflammation may be a crucial factor. Accordingly, the possibility that physical activity or pharmacological agents that increase insulin sensitivity also improve endothelial function, or vice versa, has been investigated. Many different alterations in life style and drugs that improve endothelial function are known to lower the risk of contracting diabetes. In this review, the pharmacological treatment available against type 2 diabetes mellitus is discussed with particular emphasis on its impact on the endothelium.