Effect of captopril on kidney function in insulin-dependent diabetic patients with nephropathy

Abstract

The influence of angiotensin II on kidney function in diabetic nephropathy was assessed by studying the effect of 12 weeks’ monotherapy with captopril (25–50 mg twice a day) in 16 hypertensive insulin dependent diabetic patients with persistent albuminuria. In an initial one week randomised single blind trial of captopril versus placebo, captopril (for nine patients) reduced arterial blood pressure from 148/94 (SD11/6) to 135/88 (8/7) mm Hg (p<0.05) and albuminuria from 1549 (range 352–2238) to 1170 (297–2198) μg/min (p<0.05), while glomerular filtration rate remained stable. No significant changes occurred in seven patients treated with placebo. During the 12 weeks of captopril treatment arterial blood pressure in all patients fell from 147/94 (11/6) to 135/86 (13/7) mm Hg (p<0.01), albuminuria fell from 1589 (range 168–2588) to 1075 (35–2647) μg/min (p<0.01), and glomerular filtration rate fell from 99 (SD19) to 93 (25) ml/min/1. 73 m2 (p<0.01). The renin-angiotensin system showed suppressed plasma concentrations of angiotensin II and increased concentrations of angiotensin I and renin. The study showed that glomerular filtration rate is not dependent on angiotensin II, that captopril reduces albuminuria, probably by lowering glomerular hypertension, and that captopril represents a valuable new drug for treating hypertension in diabetics dependent on insulin with nephropathy. © 1986, British Medical Journal Publishing Group. All rights reserved.