Effects of angiotensin-converting enzyme inhibitors on the treatment of anemia with erythropoietin

Background. The hypothesis that angiotensin-converting enzyme (ACE) inhibitors interfere with the treatment of anemia with recombinant human erythropoietin (rHuEPO) remains controversial. To test this hypothesis, a retrospective analysis was conducted in a large group of hemodialysis patients with renal anemia. Methods. The effects of ACE inhibitors in these patients were evaluated by measuring the weekly increment in hematocrit (Delta Hct) values within 12 weeks of the initiation of rHuEPO treatment. Results from 2213 rHuEPO naive patients were compared between patients receiving rHuEPO alone and patients receiving both rHuEPO and ACE inhibitors. Because of the demographic differences between the two groups, a propensity score was used to eliminate the influence of confounding factors and to match the patient population in these two patient groups. Multiple regression analysis also was performed. Results. When the Delta Hct values were compared directly between the two groups or were assessed by multiple regression analysis, no effect of ACE inhibitors was observed (P = 0.941 and P = 0.308, respectively). When the effects of ACE inhibitors on the treatment of anemia with rHuEPO were analyzed in 329 patients extracted from each group by their propensity score, Delta Hct did not differ between the two groups (P = 0.355). Conclusions. These results suggest that ACE inhibitors have no effect on the rHuEPO treatment for anemia in hemodialysis patients who were treated with a relatively low dose of ACE inhibitors and low-dose rHuEPO.