LONG-TERM BENEFICIAL-EFFECTS OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITION IN PATIENTS WITH NEPHROTIC PROTEINURIA

Angiotensin-converting enzyme inhibitors (ACEI) can reduce proteinuria in diabetic and nondiabetic nephropathy. However, no studies have determined whether this antiproteinuric effect modifies the progression of renal insufficiency. We studied the evolution of 46 nondiabetic patients with nephrotic proteinuria treated with captopril for a minimum of 12 months. The follow-up period before captopril treatment was 12 to 18 months. At the end of follow-up, after captopril introduction (24.4 ± 7.6 months), proteinuria had decreased from 6.3 ± 2.5 to 3.9 ± 3.1 g/24 h (P < 0.001), with a mean decrease of 45% ± 28%. The proteinuria decrease was higher in patients with reflux nephropathy, proteinuria associated with reduction of renal mass, inactive crescentic glomerulonephritis, nephroangiosclerosis, and IgA nephropathy, whereas patients with membranous glomerulonephritis and idiopathic focal glomerulosclerosis showed a poorer response. Patients were separated according to a proteinuria reduction greater (group A, 23 patients) or lower (group B, 23 patients) than 45% of the initial value. At the end of follow-up, renal function had not significantly changed in group A with respect to values at the start of treatment: serum creatinine (SCr) was 229 ± 167 gmol/L (2.6 ± 1.9 mg/dl) versus 203 ± 97 µmol/L (2.3 ± 1.1 mg/dL), and creatinine clearance (CrCI) was 0.80 ± 0.52 mL/s (48 ± 31 mL/min) versus 0.87 ± 0.47 mL/s (52 ± 28 mL/min). The slope of the reciprocal of Scr (1/SCr) showed a significantly beneficial change after captopril introduction. However, in group B, renal function continued to deteriorate as in the pretreatment period: SCr 300 ± 221 µmol/L (3.4 + 2.5 mg/dL) versus 159 ± 61 µmol/L (1.8 ± 0.7 mg/dL) (P < 0.01), and CrCI was 0.73 ± 0.52 mL/s (44 ± 31 mL/min) versus 1.00 + 0.49 mL/s (60 ± 29 mL/min) (P < 0.01) and the slope of 1/SCr did not show a beneficial variation. There were no differences between groups in regard to age, sex, captopril dose, blood pressure, or renal function at the start of treatment. The decrease of proteinuria was unrelated to blood pressure changes. Group A patients had significantly higher serum total proteins and albumin levels than group B. Serum cholesterol and triglycerides showed a decrease with captopril treatment in both groups. In summary, a significant antiproteinuric effect of captopril in patients with nephrotic proteinuria is accompanied by an arrest in the progression of renal insufficiency; in addition, an amelioration of lipid profile was observed during the treatment. © 1992, National Kidney Foundation. All rights reserved. All rights reserved.