Diabetes and hypertension.

Diabetes mellitus and hypertension constitute two powerful independent risk factors for cardiovascular, renal and atherosclerotic disease. The frequent occurrence of the two diseases in the same individual doubles the risk of cardiovascular death, as well as substantially increasing the frequency of transient ischemic attacks, strokes, peripheral vascular disease with lower extremity amputations, as well as end-stage renal disease and blindness. Although hypertension usually occurs in IDDM in association with renal disease, in NIDDM the evolution of hypertension appears to be multifactorial and independent of renal disease. Obesity appears to be dissociable from hypertension and NIDDM with a common link between obesity, hypertension and NIDDM appearing to be hyperinsulinism and insulin resistance. It has been suggested that hyperinsulinism and insulin resistance may lead to hypertension through altered intracellular calcium metabolism, enhanced renal sodium reabsorption, or through an effect of insulin upon lipid and/or catecholamine metabolism. Further, insulin itself may have a direct effect upon the atherosclerotic process in the hypertensive diabetic patient. These considerations have been taken into account in the structuring of antihypertensive therapy in Type I and Type II Diabetes Mellitus.