Treatment of Hypertension With Renin-Angiotensin System Inhibitors and Renal Dysfunction: A Systematic Review and Meta-Analysis

BACKGROUND To determine whether inhibitors of the renin-angiotensin system (RAS) reduce the incidence of renal dysfunction when compared to other antihypertensive treatments in patients with essential hypertension and no pre-existent renal disease. METHODS The search strategy used the Cochrane Library, Medline, previous meta-analyses, and journal reviews. The selection criteria included randomized, controlled trials of antihypertensive drugs that compared a RAS inhibitor with another treatment in essential hypertension. Studies that specifically enrolled only patients with diabetes or renal disease were not included. The quality assessment and data extraction of studies were performed by two independent reviewers. Effects on dichotomous renal outcome (serum creatinine (SCreat) higher than a prespecified value, doubling of SCreat or end-stage renal disease) and secondary continuous marker of renal outcome (change in SCreat) were calculated using Peto's method. RESULTS 33,240 patients met the inclusion criteria for studies with a dichotomous outcome and 10,634 patients for studies with a continuous outcome. The mean follow-up was 42 +/- 13 months. Patients randomized to RAS inhibitors did not show a significant reduction in the risk of developing renal dysfunction as compared to other antihypertensive strategies (odds ratio = 1.05; 95% confidence interval (CI) 0.89-1.25;P = 0.54). There was no significant difference in change of SCreat between groups (mean difference = 0.0005 mg/dl; 95% CI -0.0068 to 0.0077 mg/dl; P = 0.91). CONCLUSION In patients with essential hypertension and no pre-existent renal disease, prevention of renal dysfunction is not significantly different with RAS inhibitors when compared to other antihypertensive agents.