Effects of angiotensin II receptor blocker (irbesartan) on peritoneal membrane functions

Angiotensin II receptor blockers (ARBs) are effective in controlling blood pressure and have been shown to reduce proteinuria with fewer adverse effects than angiotensin converting enzyme inhibitors. In the present prospective study, we evaluated the action of irbesartan, an ARB with a long half life, on proteinuria, peritoneal protein losses, and peritoneal transport in patients with chronic renal failure (CRF) undergoing peritoneal dialysis (PD). We enrolled 15 stable patients (11 with diuresis of more than 500 mL/day; 40% women; 40% with diabetes) into the study. Mean age of the patients was 65 +/- 15 years, and mean time on PD was 33 +/- 21 months. The study was performed in two stages. In stage I, patients received no irbesartan. In stage II, patients received 30 days of treatment with irbesartan (145 +/- 72 mg/day). After treatment with irbesartan, and no changes in blood pressure level as compared with baseline, we observed a reduction in proteinuria (r = 0.690, p < 0.05), decreased peritoneal protein losses at 4 hours' and 24 hours' dwell time (r = 0.910 and r = 0.930, p < 0.001), decreased peritoneal Kt/V(r = 0.586, p < 0.05), and increased peritoneal creatinine clearance (r = 0.943, p < 0.001). Levels of serum albumin (r = 0.630, p < 0.05), prealbumin (r = 0.810, p < 0.001), and transferrin (r = 0.551, p < 0.05) increased after treatment with irbesartan. We conclude that treatment with irbesartan in patients with CRF undergoing PD modifies peritoneal transport and reduces peritoneal and urinary protein loss. This effect probably has a positive impact on nutritional parameters. Further studies are required to elucidate the mechanisms involved.