Insulin resistance in systemic hypertension: pharmacotherapeutic implications.

Systemic hypertension, a vascular disease with multiple origins, now is being linked to subtle abnormalities in glucose metabolism, which include insulin resistance and hyperinsulinemia. These conditions often occur together in patients with obesity, noninsulin-dependent diabetes, or both. Hyperinsulinemia and insulin resistance may cause systemic hypertension through multiple mechanisms. Insulin has a salt-retaining effect on the kidney. Also, insulin can augment catecholamine release, increase vascular sensitivity to vasoconstrictor substances, and decrease vascular sensitivity to vasodilator substances. In addition, insulin can increase production of tissue growth factors and help retain sodium and calcium in cells. Insulin resistance in patients can be treated with regular aerobic exercise, weight reduction, and a high-fiber diet. Pharmacologic approaches include hypoglycemic drugs, weight-reducing agents, and certain antihypertensive drugs that may have a favorable impact on both blood pressure and insulin resistance.