The effect of antihypertensive agents on new-onset diabetes mellitus: time to amend the guidelines?

Recent large hypertension trials have shown great differences in incidence of new-onset diabetes mellitus among patients receiving different antihypertensive drug therapies. The incidence of diabetes is unchanged or increased by the use of thiazide diuretics and beta-adrenoceptor antagonists (beta-blockers) and unchanged or decreased by ACE inhibitors, calcium channel blockers (CCBs), and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers). Recent results from ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) showed superiority of the 'new' combination of CCBs and ACE inhibitors over the 'old' or 'conventional' combination of beta-blockers and diuretics. In this review, the results from some of the large hypertension trials are discussed, and the hypotheses on how different antihypertensive drug regimens can affect glucose homeostasis are considered. The question now is whether the results from these recent trials should affect the choice of antihypertensive treatment, particularly for special groups. However, the key goal is still to reduce BP, and this usually requires combinations of drugs.