Background: The renoprotective effect of angiotensin II antagonists has been demonstrated in type 2 diabetic patients with nephropathy but similar data on angiotensin-converting enzyme (ACE) inhibitors are limited. We examined the efficacy and tolerability of fosinopril, an ACE inhibitor with dual hepatic and renal clearance, in 38 type 2 diabetic patients with moderate renal impairment (plasma creatinine 130-300 micromol/l) over a 2-year period.
Methods: This was a single-centre, randomized, double-blinded, placebo-controlled trial comparing fosinopril 20 mg daily vs. placebo in addition to conventional antihypertensive treatment over a 2-year period. The primary endpoints were the rate of change and the percentage change in both 24-h urinary albumin excretion (UAE) and creatinine clearance (CrCl).
Results: The mean age of the patients was 65 +/- 6 years (range 47-76 years, median 66 years) and plasma creatinine 190 +/- 49 micromol/l. For similar blood pressure control, the percentage change of UAE in patients with microalbuminuria was greater in the fosinopril than the placebo group (-24.2 +/- 28.8 vs. 11.6 +/- 42.1%, p = 0.003 after adjustment for baseline covariates). In the fosinopril group, the rate of change of endogenous CrCl was slower than the placebo group (-0.07 +/- 0.19 vs. -0.24 +/- 0.35 ml/min/week, p = 0.026). The incidence of adverse events was similar between the two groups.
Conclusions: Fosinopril treatment reduced albuminuria and rate of decline in renal function in type 2 diabetic patients with moderate renal insufficiency and did not increase the incidence of adverse events.