New onset diabetes during antihypertensive therapy

New onset diabetes (NOD) is common among hypertensive patients, whether they are being treated for hypertension or not, and is associated with subsequently increased cardiovascular disease (CVD). Thiazide-like diuretics and beta-blockers are more likely to provoke hyperglycemia when compared with drugs that block the renin-angiotensin system, and calcium channel blockers. However, in contrast to the NOD arising during treatment with other antihypertensive drugs, the NOD that occurs during diuretic treatment, has not been shown to increase CVD, either in clinical trials, or during longer observational studies. In fact, blood pressure reduction achieved by diuretic treatment may avert the expected increase of CVD in NOD. Conventional blood pressure reduction (along with lipid lowering) is the proven approach to preventing CVD in diabetes, in whatever circumstances the diabetes occurs. Apprehensions relating to the potential onset of NOD should not influence the choice of the initial antihypertensive treatment choice, nor should it invariably lead to discontinuation of diuretics (although such a step may reverse hyperglycemia). NOD can also sometimes be eliminated by correcting hypokalemia with a potassium-sparing diuretic, and/or potassium supplementation, or by adding a potassium-conserving antihypertensive drug such as an ACEI, ARB, or an anti-aldosterone agent. If all these stratagems fail (or are unsuitable), and the diuretic is essential to blood pressure control, then hypoglycemic therapy is indicated. NOD does adversely affect quality of life, and is not to be accepted lightly. However, diuretic-induced hyperglycemia can be managed, and should be tolerated if a diuretic is essential for blood pressure control. In summary, the potential for occurrence of NOD certainly needs consideration, but it is not an insurmountable challenge, and must not compromise aggressive blood pressure control, which remains the primary tool for antihypertensive care.