Antihypertensive Therapy and New-Onset Diabetes

Abstract

Numerous analyses demonstrate that antihypertensive therapies promote development of type-2 diabetes mellitus. This is particularly true in obesity patients with impaired glucose tolerance. Numerous randomized studies provide evidence that the use of diuretics and β blockers produces the highest risk for conversion to diabetes, whereas angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARB) lead to less new-onset diabetes compared to placebo. β Blockers worsen glycemic control through worsening of insulin resistance and reduced flow to muscle whereas diuretics impair glucose metabolism, in part, through reducing potassium. Thus, diuretics and β blockers not only increase glucose in those with diabetes but also promote the development of new-onset diabetes in those with glucose intolerance. Given the latest guidelines, β blockers are not indicated for routine use to treat hypertension and diuretics should be reserved for second- or third-line agents. Data from the NICE guidelines in the United Kingdom put diuretics as third-line agents after blockers of the renin–angiotensin system and calcium antagonists. One must keep in mind, however, that in multiple trials where diuretics were shown to worsen glycemic control, there was a mortality benefit as increasing doses of oral hypoglycemic medications were used. In short, while these agents can be avoided as initial agents for treatment of hypertension, many patients with heart or kidney disease, i.e., eGFR < 60 mL/min, will require diuretic therapy to control blood pressure.