CAPTOPRIL AND ATENOLOL ARE EQUALLY EFFECTIVE IN RETARDING PROGRESSION OF DIABETIC NEPHROPATHY - RESULTS OF A 2-YEAR PROSPECTIVE, RANDOMIZED STUDY

The progression of diabetic nephropathy can be positively influenced by maintaining a low blood pressure level. This has been shown in studies with conventional antihypertensive treatment as well as with ACE inhibitors. Whether the latter group of drugs is more effective remains to be proven and was the aim of our study. In a prospective randomized study we compared the effects of ACE inhibition and beta-blockade on retarding progression of renal function in IDDM patients with an early stage of overt diabetic nephropathy. Twenty-nine patients were studied for 2 years, 15 were randomized for treatment with captopril and 14 for atenolol. Every 6 weeks blood pressure and urinary albumin and total protein excretion were measured. GFR was measured every 6 months as Cr-51-EDTA clearance. Baseline values for blood pressure, renal function and albuminuria were identical in the two groups. The effect of both drugs on blood pressure was not significantly different. In the captopril-treated patients MAP before and after 2 years was 110 +/- 3 (SEM) and 100 +/- 2 mm Hg, respectively and in the atenolol-treated patients 105 +/- 2 vs 101 +/- 2 mm Hg. Both drugs reduced alb uminuria and total proteinuria to the same extent. With captopril albuminuria decreased from 1549 (989-2399) to 851 (537-1380) mg/24 h and proteinuria from 2.5 (1.6-3.8) to 1.2 (0.8-1.8) g/24 h. With atenolol albuminuria decreased from 933 (603-1445) to 676 (437-1047) mg/24 h and proteinuria from 1.5 (1.0-2.4) to 0.9 (0.6-1.5) g/24 h. The rate of decline of GFR was similar with both treatments, on captopril -4.9 +/- 2.1 and on atenolol -3.7 +/- 1.6 ml.min(-1).year(-1). No major side effects with either drug were observed. We conclude that, in this 2-year study, captopril and atenolol are equally effective in retarding progression of diabetic nephropathy.