Clinical Question: Are angiotensin receptor blockers (ARBs) as good as angiotensin-converting enzyme (ACE) inhibitors at preventing the progression of nephropathy?

Setting: Outpatient (any)

Study Design: Randomized controlled trial (double-blinded)

Allocation: Uncertain

Synopsis: In this study, 250 participants with diabetes who had mild to moderate hypertension and evidence of early nephropathy (i.e., urinary albumin excretion rate between 11 and 999 mcg per minute and a serum creatinine level of less than 1.6 mg per dL) were randomized to receive telmisartan in a dosage of 40 mg per day or enalapril in a dosage of 10 mg per day. Blood pressure medicines other than an ACE inhibitor or ARB could be added at the discretion of the treating physician to control blood pressure. The primary outcome was the glomerular filtration rate.

There was a high dropout rate, and the last observation was appropriately carried forward for the analysis. The results for only those patients with complete data also were reported. In both cases, almost no difference in glomerular filtration rate was noted for the first two years, with a trend toward greater benefit for enalapril that almost became significant at four years and declined slightly at five years.

Bottom Line: Despite a relatively low dosage of 10 mg taken once a day, enalapril was at least as effective as telmisartan and showed a trend toward greater benefit in preventing decline in glomerular filtration rate. Although this study measured a disease-oriented end point, its results are consistent with the body of literature that supports the less expensive ACE inhibitors as the drug of choice over ARBs. (Level of Evidence: 1b)