Renoprotective effects of telmisartan in patients with advanced chronic kidney disease

Background: Angiotensin II receptor blockers (ARBs) provide renoprotective effects in patients with mild-to-moderate chronic kidney disease (CKD). However, there have been few reports regarding whether ARBs show clinical efficacy and safety in patients with advanced CKD. Methods: Seventy-two hypertensive patients with Stages 3 - 4 CKD receiving no ARBs were enrolled in this study and observed up to 48 months. Telmisartan was added to conventional antihypertensive agents (n = 36, mean estimated glomerular filtration ratio [eGFR] 19.7 ml/min/1.73 m 2 ) whilst the remaining control patients were not treated with ARBs (n = 36, mean eGFR 19.2 ml/min/1.73 m 2 ). Urinary protein excretion, kidney function, and the occurrence of end-stage renal disease requiring renal replacement therapy, hyperkalemia, and death were analyzed. Results: Baseline characteristics of each group were similar. During the observation period, the blood pressures of each group decreased at similar rates. In the telmisartan group, 17 patients (47.2%) were introduced to renal replacement therapy, as compared with 31 patients (86.1 %) in the control group (relative risk 0.55, 95% confidence interval 0.19-0.92, p < 0.05). Telmisartan significantly reduced proteinuria levels (from 3.47 ± 3.00 to 2.41 ± 2.46 g/g · creatinine, p < 0.05) and was associated with a reduction of 49.6% in the decline rate of eGFR. The incidence of major adverse events in both groups was similar. Conclusions: The addition of telmisartan to conventional antihypertensive therapy is associated with significant improvement in kidney outcome without increased incidence of adverse effects, even in patients with advanced CKD.