Effects of antihypertensives on glucose metabolism.

Treatment with different antihypertensive drug classes has varied effects on glucose metabolism. Thiazide diuretic use in hypertensives has been associated with the development of glucose intolerance and diabetes. Some findings suggest that the probability of worsening glucose metabolism and the development of new diabetes after thiazide initiation is associated with increasing body mass index. Nonselective or beta(1) selective beta-blockers may also lead to decreased insulin sensitivity in hypertensive patients. Newer beta-blockers that cause vasodilatation and beta-blockers that have intrinsic sympathomimetic activity may not have these deleterious effects on insulin sensitivity and glucose metabolism. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers may exert beneficial effects on glycemic control through a variety of mechanisms related to the inhibition of angiotensin II. These agents may be particularly useful in patients with microalbuminuria to slow the progression of renal disease. While there may be some small differences among different classes of calcium channel blockers, there is little net effect of these agents on glucose metabolism. The prevalence of obesity, hypertension, and type 2 diabetes mellitus is increasing in the US. In this setting, it is important to individualize antihypertensive therapy and to monitor its metabolic consequences so that potential adverse effects that would negate some of the benefits of blood-pressure lowering are minimized.