Carbohydrate metabolism in hypertension: influence of treatment.

Epidemiologic studies suggest a close association between hypertension, obesity, and diabetes. It has been demonstrated that essential hypertension, per se, is an insulin-resistant state. However, the pathogenesis of the association between insulin resistance and hypertension is poorly understood. Elevated plasma insulin levels may contribute to the development of hypertension through renal sodium reabsorption, the sympathetic nervous system, the transmembranous cation transport, the renin-angiotensin system, the cardiovascular reactivity, and the atrial natriuretic peptide. Diuretics, beta-blockers, calcium antagonists, angiotensin-converting enzyme (ACE) inhibitors, and alpha 1-antagonists are first-choice drugs in the management of hypertension. Diuretics, except indapamide, impair insulin sensitivity and glucose tolerance. The same negative effects, exerted by beta-blockers, are reduced employing those with selective activity. With few exceptions, calcium antagonists have no adverse influence on carbohydrate metabolism. ACE inhibitors and alpha 1-antagonists do not influence or even improve glucose metabolism.