Effect of quinapril on the albumin excretion rate in patients with mild to moderate essential hypertension. Multicenter Study Group.

In patients with essential hypertension, correlations have been reported between the albumin excretion rate (AER) and ambulatory and casual blood pressure. Microalbuminuria has been indicated as a possible predictor of cardiovascular morbidity and mortality. The objective of this trial was to evaluate the effect of quinapril, an angiotensin converting enzyme inhibitor with high tissue affinity for the enzyme, on the AER in patients with mild to moderate essential hypertension and no evidence of diabetes mellitus. In this 12 week, 24 center study, quinapril was administered to 213 patients and titrated to 10, 20, or 40 mg/day alone or 20 mg/day plus 12.5 mg/day hydrochlorothiazide. Overall, blood pressure was reduced from 155.2 +/- 18.1/101.8 +/- 6.7 mm HG (mean +/- SD) to 144.4 +/- 17.8/92.3 +/- 8.9 mm HG (P = .0001) and AER decreased from 20.6 +/- 24.3 mg/24 h to 14.5 +/- 15.4 mg/24 h (P = .0001). The BP reductions were significant in all age groups. AER at endpoint was reduced 37.5% in elderly, 29.8% in middle-aged, and 11.8% in young patients from 32.5 +/- 45.0 mg/24 h, 19.1 +/- 20.9 mg/24 h, and 16.1 +/- 16.9 mg/24 h, respectively. The AER decreased in 60% of patients who had normal AER (0 to 30 mg/24 h), in 79% of those who had microalbuminuria (30 to 300 mg/24 h), and in 90% of those who had proteinuria (> 300 mg/24 h) at baseline. Baseline log-AER correlated with SBP (P = .0126, R = 0.19) and creatinine clearance (P = .026, R = 0.17), while endpoint log-AER correlated with SBP (P = .0015, R = 0.25) and DBP (P = .03, R = 0.17). In summary, we showed, in a large group of patients with mild to moderate essential hypertension and no evidence of diabetes mellitus, that quinapril not only lowers BP significantly but also reduces microalbuminuria.