Hypertension and diabetes: epidemiologic aspects as a guide to management.

Elevated blood pressure (BP) is an important risk factor for both the large- and small-vessel complications of diabetes. The following pathogenetic mechanisms have been proposed to explain the association between hypertension and diabetes: increases in total body exchangeable sodium associated with hyperglycemia, alterations in the function of the renin-angiotensin-aldosterone system, and the possible role of insulin resistance. Several prospective studies have shown that both systolic and diastolic BP are important predictors of ischemic heart disease, stroke, and renal disease mortality in diabetic patients. In spite of this strong association, there is little evidence from randomized controlled trials on the efficacy of BP lowering in the prevention of cardiovascular mortality in diabetic patients. Prospective data from the WHO Multinational Study do not provide clear evidence of benefit from treating diastolic BP < 95-100 mm Hg in patients with noninsulin-dependent diabetes.