Effects of amlodipine fosinopril combination on microalbuminuria in hypertensive type 2 diabetic patients

Abstract Background The aim of this study is to compare the long-term effect of amlodipine and fosinopril in monotherapy or in combination on urinary albumin excretion (UAE) in hypertensive diabetic patients. Methods We selected 453 hypertensive patients with type 2 diabetes and microalbuminuria and randomized them to amlodipine (5 to 15 mg/day), fosinopril (10 to 30 mg/day), or amlodipine plus fosinopril (5/10 to 15/30 mg/day) for a 3-month titration period. The nonresponder patients or those complaining of side effects during the titration period were discontinued (n = 144); the remaining 309 patients were enrolled in the trial and treated with the same therapy for 4 years. Every 6 months, blood pressure (BP), heart rate (HR), UAE, creatinine clearance, and glycosylated hemoglobin (HbA1c) were evaluated. Results The combination therapy was more effective in reducing BP than either drug alone at any time of the study without affecting glucose homeostasis. All three treatments provided a significant decrease in UAE during the 48-month study period. However, this effect was more pronounced and became evident earlier with fosinopril than with amlodipine monotherapy (after 3 v 18 months of therapy). In addition, the combination therapy provided a greater antialbuminuric effect than the single drugs. This could be due to the greater antihypertensive effects, although other drug-specific effects cannot be excluded. The cardiovascular outcomes were similar in the amlodipine and in the fosinopril group, but they were lower in the combination group. Conclusions These results strengthen the rationale to use a calcium-antagonist/angiotensin converting enzyme inhibitor combination in the treatment of hypertensive patients with type 2 diabetes.