IMPACT OF LISINOPRIL AND ATENOLOL ON KIDNEY-FUNCTION IN HYPERTENSIVE NIDDM SUBJECTS WITH DIABETIC NEPHROPATHY

Diabetic nephropathy is characterized by hypertension and a relentless decline in kidney function. Angiotensin-converting enzyme inhibitors have been claimed to preserve kidney function better than an equal blo od pressure (BP) reduction with conventional antihypertensive treatmen t (renoprotection). We compared the effect on kidney function of lisin opril (10-20 mg/day) and atenolol (50-100 mg/day) in hypertensive NIDD M patients (mean age 60 +/- 8 years) with diabetic nephropathy, Forty- three (21 Lisinopril and 22 atenolol) patients were enrolled in a 1-ye ar randomized double-blind parallel study. Eight patients dropped out, and the results for the remaining 35 patients (16 lisinopril and 19 a tenolol) are presented. Diuretics were required in 10 of 16 Lisinopril patients and 12 of 19 atenolol patients. The following variables were measured: 24-hour ambulatory BP (Takeda TM2420), albuminuria (enzyme- linked immunosorbent assay), fractional albumin clearance, and glomeru lar filtration rate (GFR) ([Cr-51]EDTA technique). The average reducti on in mean arterial BP during the 12 months was identical in the two g roups 12 +/- 2 vs. 11 +/- 1 mmHg in the lisinopril and atenolol group, respectively. Albuminuria was on average reduced 45% in the lisinopri l group vs. 12% in the atenolol group (P < 0.01), and fractional album in clearance was on average reduced 49% in the lisinopril group vs. 1% in the atenolol group (P < 0.05). GFR declined identically in the two groups 11.7 +/- 2.3 vs. 11.6 +/- 2.3 ml.min(-1).year(-1) in the lisin opril and atenolol groups, respectively. In conclusion, both drugs arr ested the progressive rise in albuminuria characteristically found in diabetic nephropathy, but lisinopril reduced albuminuria more than an equally effective antihypertensive treatment with atenolol. Longer fol low-up is required to clarify if this difference is of importance for the progression in kidney function.