ANGIOTENSIN-CONVERTING ENZYME-INHIBITION IN DIABETIC NEPHROPATHY - 10YEARS EXPERIENCE

The aim of our prospective study was to evaluate putative progression promoters, kidney function, and prognosis during long-term treatment w ith angiotensin-converting enzyme inhibition in insulin-dependent diab etes mellitus patients suffering from diabetic nephropathy. Eighteen c onsecutive hypertensive insulin-dependent diabetes patients with nephr opathy (mean age, 33 years) who had not been treated previously were a ll treated with captopril in combination with frusemide or bendrofluaz ide. The four patients who were refractory to this regimen also receiv ed nifedipine. Treatment was continued for a median of 8.9 years (rang e, 6.3 to 9.8, years). Renal function was assessed every 6 months by m easurement of glomerular filtration rate (GFR) (single-bolus Cr-51-EDT A technique) and albuminuria by radioimmunoassay. Baseline values (+/- SE) were mean arterial blood pressure 146/93 +/- 3/1 mm Hg, albuminuri a (geometric mean +/- antilog SE) 982 +/- 1.2 mu g/min, and GFR 98 +/- 5 mL/min/1.73 m(2), Angiotensin-converting enzyme inhibition induced a significant reduction during the whole treatment period of blood pre ssure (137/85 +/- 3/1 mm Hg; P < 0.01) and albuminuria (392 +/- 1.4 mu /min; P < 0.01), and the rate of decline in GFR was 4.4 +/- 0.7 mL/min /yr, in contrast to previous reports of 10 to 14 mL/min/yr (natural hi story). Univariate analysis revealed a significant correlation between the rate of decline in GFR and mean arterial blood pressure (r = 0.58 , P = 0.01), albuminuria (r = 0.67, P < 0.01), hemoglobin A(1c) (r = 0 .69, P < 0.01), and serum total cholesterol concentration (r = 0.51, P < 0.05). A multiple linear regression analysis including the four abo ve-mentioned progression promoters showed that only albuminuria (P < 0 .05) and hemoglobin A(1c) (P < 0.01) correlated significantly with the rate of decline in GFR, explaining two thirds of the progression, The cumulative death rate was 11% (95% confidence interval, 0 to 25) 10 y ears after onset of nephropathy in patients receiving angiotensin-conv erting enzyme inhibition and diuretics, in contrast to previous report s of 50% to 77% 10 years after onset of nephropathy (natural history), In conclusion, long-term antihypertensive treatment with antiotensin- converting enzyme inhibition frequently combined with diuretics protec ts kidney function and enhances survival in hypertensive insulin-depen dent diabetes patients with diabetic nephropathy. (C) 1995 by the Nati onal Kidney Foundation, Inc.