Sodium metabolism, hypertension, and diabetes

The hypertension that frequently accompanies diabetes mellitus is characterized by abnormalities of sodium (Na) metabolism at all physiologic levels: whole-body, renal, and cellular. The most consistently described abnormality is an expansion of exchangeable Na, which seems to be closely associated with increased proximal renal tubular Na reabsorption and suppression of membrane sodium-potassium ATPase activity in circulating cells. Although recent interest has focused almost exclusively on the role of hyperinsulinemia in promoting renal Na retention and causing expansion of total body Na and Na-dependent hypertension, there is evidence that other factors in addition to insulin excess are involved.