Outcomes With Nifedipine GITS or Co-Amilozide in Hypertensive Diabetics and Nondiabetics in Intervention as a Goal in Hypertension (INSIGHT)

Abstract

To investigate the impact of treatment on cardiovascular mortality and morbidity, we assessed outcomes in patients with hypertension and diabetes who received co-amilozide or nifedipine in the International Nifedipine GITS Study: Intervention as a Goal in Hypertension. Participants had to be 55 to 80 years of age, with hypertension (≥150/95 or ≥160 mm Hg) and at least one additional cardiovascular risk factor. Patients received 30 mg nifedipine once daily or co-amilozide (25 mg hydrochlorothiazide and 2.5 mg amiloride) daily. Doses were doubled if target blood pressures (P =1.00). A significant benefit for nifedipine-treated patients was seen for the composite secondary outcome (14.2% versus 18.7%; relative risk, 0.76, 95% CI, 0.59 to 0.97; P =0.03). Among patients without diabetes at baseline (n=5019), there was a significant difference in the incidence of new diabetes (nifedipine 4.3% versus co-amilozide 5.6%, P =0.023). Nifedipine GITS once daily is as effective as diuretic therapy in reducing cardiovascular complications in hypertensive diabetics. Nifedipine-treated patients were also less likely to have diabetes or have secondary events (a composite of all-cause mortality, death from a vascular cause, and death from a nonvascular cause) than co-amilozide recipients. Our results suggest that nifedipine could be considered as first-line therapy for hypertensive diabetics.