HIGH-DOSE ENALAPRIL IMPAIRS THE RESPONSE TO ERYTHROPOIETIN TREATMENT IN HEMODIALYSIS-PATIENTS

Background. The resistance to recombinant human erythropoietin (rHuEpo ) therapy in haemodialysis (HD) patients has multifactorial aetiologie s: erythropoietin insufficiency, dialysis insufficiency, iron deficien cy, and secondary hyperparathyroidism. Angiotensin-converting enzyme ( ACE) inhibitors induce anaemia in patients with essential hypertension , congestive heart failure, chronic renal insufficiency, and renal tra nsplants. Data exist suggesting that ACE inhibitors impair erythropoie sis in HD patients. Therefore the aim of this study was to investigate the impact of enalapril on rHuEpo requirement. Methods. In the presen t prospective non-randomized study of 12 months, we compared the effec ts of enalapril and nifedipine on rHuEpo requirement in 40 hypertensiv e patients receiving rHuEpo for more than 6 months on maintenance haem odialysis. Twenty normotensive rHuEpo-dependent patients served as a c ontrol group. All patients with severe hyperparathyroidism or iron def iciency were excluded. Results. The mean (+/- SD) haemoglobin concentr ation was >10 g/dl in all groups. The mean weekly rHuEpo dose increase d in the enalapril group (P<0.0001 vs before) and remained constant in the nifedipine and control groups (P=NS vs before). Statistically, th ere was no differences with regard to iPTH levels, dialysis parameters , iron status, and underlying renal diseases among all groups. Conclus ion. High-dose enalapril increases rHuEpo requirement and should be re served for dialysis patients with hypertension uncontrollable with oth er antihypertensive medications or dialysis patients with cardiac fail ure.