Diabetes mellitus and hypertension are two of the most common diseases in Westernized, industrialized civilizations, and the frequency of both diseases increases with increasing age. Diabetes mellitus is characterized by elevated blood glucose levels (hyperglycemia) resulting from defects in insulin secretion, insulin action or both, and associated with a considerably increased cardiovascular risk, peripheral vascular diseases, stroke, retinopathy, and nephropathy. Two types of diabetes mellitus are recognized based on the presumed etiology. In type 1 diabetes, the body fails to produce insulin as a result of an auto-immune reaction that destroys the islet cells in the pancreas that produce insulin, and daily insulin injections are required. Type 1 diabetes is usually diagnosed during childhood or early adolescence and it affects about 1 in every 600 children. Type 2 diabetes is the result of failure to produce sufficient insulin and insulin resistance. Elevated blood glucose levels are managed with reduced food intake, increased physical activity, and eventually oral medications or insulin. Type 2 diabetes is typically diagnosed during adulthood. However with the increasing incidence of childhood obesity and concurrent insulin resistance, the number of children diagnosed with type 2 diabetes has also increased worldwide.
The hallmark of hypertension in type I and type II diabetics appears to be increased peripheral vascular resistance. Increased exchangeable sodium may also play a role in the pathogenesis of blood pressure in diabetics. Evidence is accumulating that insulin resistance, or hyperinsulinemia, may play a key role in the pathogenesis of hypertension in both subtle and overt abnormalities of carbohydrate metabolism. Population studies suggest that elevated insulin levels, which often occurs in type II diabetes mellitus, is an independent risk factor for cardiovascular disease. Other cardiovascular risk factors in diabetic individuals include abnormalities of lipid metabolism, platelet function, and clotting factors.