Both thiazide diuretics and β-blockers taken to treat hypertension appear to raise the risk of type 2 diabetes, reported Dr. Eric N. Taylor of Harvard Medical School, Boston, and his associates.
The researchers used data from three large cohort studies to determine whether various antihypertensive agents were associated with incident cases of type 2 diabetes. They analyzed data on more than 14,000 younger women (aged 25–42 at baseline) in the Nurses' Health Study II, more than 41,000 older women (aged 30–55 years at baseline) in the Nurses' Health Study I, and more than 19,000 men (aged 40–75 years at baseline) in the Health Professionals Follow-Up Study.
All the subjects were taking medication for hypertension. During follow-ups of 10 years (NHS II participants), 8 years (NHS I participants), and 16 years (HPFS participants), 3,589 developed type 2 diabetes.
The use of thiazide diuretics significantly raised the risk of incident diabetes in all three cohorts. The use of β-blockers was not assessed separately from other antihypertensives in the younger women, but it significantly raised the risk of incident diabetes in the older women and in the men, Dr. Taylor and his associates wrote (Diabetes Care 2006;29:1065–70).
There was no link between the use of calcium channel blockers or other antihypertensive medications and diabetes risks. The results suggest that patients whose hypertension is treated with thiazide diuretics or β-blockers “merit increased surveillance for diabetes,” the investigators said.