New-onset diabetes in treated hypertensive patients.

Interpretation of some recent trials in hypertension opened a debate on the clinical value of new-onset diabetes in treated hypertensive patients. It is not completely clear whether certain antihypertensive drug classes are associated with a higher risk for developing type 2 diabetes when compared with other classes. Some longitudinal studies suggest that new-onset diabetes in treated hypertensive subjects carries a risk for subsequent cardiovascular disease similar to that of previously known diabetes. In a study, plasma glucose before treatment and diuretic treatment were independent predictors of new-onset diabetes in hypertensive patients, independent of confounding factors. We estimated that one cardiovascular event associated with new-onset diabetes might be prevented for every 385 to 449 patients treated with "new," rather than "old," antihypertensive drugs for approximately 4 years. These observations suggest that concern about the risk for new-onset diabetes should prompt a more judicious use of diuretics and beta-blockers in the treatment of hypertension. These drugs should be given cautiously in subjects who are at increased risk for new-onset diabetes, owing to impaired fasting glucose or obesity. The lowest effective dose should be used, and plasma glucose should be carefully monitored.