The effect of antihypertensive drugs and drug combinations on the incidence of new-onset type-2 diabetes mellitus

Purpose To evaluate the effect of antihypertensive drugs on new-onset type-2 diabetes. Methods This was a cohort study using the UK General Practice Research Database (GPRD). Patients newly diagnosed with hypertension between 1991 and 2001, and treated with antihypertensive drugs, were included. Type-2 diabetes mellitus was identified based on a physician diagnosis or an anti-diabetic drug prescription. Antihypertensive treatments were classified as: ACE inhibitors (ACE-Is), beta blockers, calcium channel blockers (CCB), thiazides, all other drugs, and their combinations. Results A total of 2706 incident diabetes cases were identified in 98 629 hypertensive patients during 307 356 patient years (8.8/1000 patient years). New-onset diabetes was lower for ACE-I regimens compared with non-ACE inhibitor regimens (HR =0.90; 95%CI: 0.82-0.99). CCB monotherapy (HR = 1.27; 95%CI: 1.07-1.51) had an increased risk of diabetes compared with ACE-I monotherapy. ACE-I plus thiazide had the lowest risk of diabetes among double combinations, followed by ACE-I plus beta blocker, and ACE-I plus CCB. Double combinations with an ACE-I had 0.79 (95%CI: 0.67-0.92) times the risk compared with non-ACE inhibitor combinations. The risk of new-onset diabetes was significantly higher for,8 blocker plus thiazide (HR = 1.37; 1.10-1.70), CCB plus thiazide (HR = 1.44; 95%CI: 1.13-1.83), but not 6 blocker plus CCB (HR = 1.30; 95%CI: 0.99-1.70) compared with ACE-I plus thiazide. Conclusions Antihypertensive drug combinations including an ACE-I had a significantly lower risk of new-onset diabetes than antihypertensive drug combinations without an ACE-I. Copyright (c) 2007 John Wiley & Sons, Ltd.