Background: The aim of the present study was to investigate the effect of losartan on the progression of renal function in non-diabetic patients with chronic renal failure in an open, prospective, follow-up study of 1 year.
Methods: Twenty-nine hypertensive patients (14 females and 15 males; mean age 63 years.) with non-diabetic chronic renal failure of several causes received losartan 50 mg/day (plus other antihypertensive agents if needed) and were followed-up prospectively during 13+/-1 months. Eighteen patients received angiotensin-converting enzyme inhibitors plus other antihypertensive drugs at baseline. Patients had been followed-up for 44+/-4 months prior to the treatment with losartan. The rate of progression of renal insufficiency was evaluated as the slope of the reciprocal of serum creatinine vs time in months.
Results: Blood pressure, creatinine clearance and urinary protein excretion at baseline and after 1 year of treatment with losartan were: 149+/-3/90+/-1 vs 142+/-2/84+/-1 mmHg (P<0.01/P<0.05), 29+/-3 vs 29+/-3 ml/min (P=NS), and 1.7+/-0.4 vs 1.2+/-0.2 g/24 h (P=0.11, NS). Serum creatinine at baseline, and after 6 months and 1 year of treatment with losartan was: 3.18+/-0.24, 3.24+/-0.27 (P=NS vs baseline) and 3.49+/-0.32 mg ml (P<0.05 vs baseline). The rate of progression of renal disease before and after 1 year of treatment with losartan was -0.0039+/-0.0058 vs -0.0012+/-0.0073 mg/month (P<0.01). Changes in proteinuria after 1 year of treatment with losartan correlated with the change in renal disease progression (r=-0.519, P<0.01).
Conclusions: The rate of progression of renal function in patients with non-diabetic chronic renal failure is slowed down after 1 year of treatment with losartan. The results of this preliminary study suggest that AT1 receptor blockade treatment offers renoprotection in this subset of patients, although these results need to be confirmed in appropriate controlled trials.