The effects of ACE inhibitor treatment and ACE gene polymorphism on erythropoiesis in chronic hemodialysis patients

: Aggravation of anemia in chronic renal failure patients by angiotensin-converting enzyme inhibitors (ACEIs) has been attributed to the inhibition of angiotensin II which facilitates erythropoietin(Epo) production. This study was aimed at evaluating whether ACEIs aggravate anemia in maintenance hemodialysis patients and to investigate the influence of ACE gene polymorphism on erythropoiesis in these patients. Ninety-one hemodialysis patients were divided into 2 groups, based on whether or not they were administered ACEIs, into the ACEI group(n = 24) and the non-ACEI group(n = 67), and comparisons were made of the doses of recombinant human Epo(rHuEpo) administered, the hematocrit(Hct) and the plasma Epo concentrations. Among the patients in the non-ACEI group, only 17 did not receive rHuEpo, while all of the patients in the ACEI group received rHuEpo. The average dose of rHuEpo was 102.7 +/- 45.4 IU/kg/week in the ACEI group and 57.8 +/- 55 IU/kg/week in the non-ACEI group and the difference between the two groups was statistically significant. A statistically significant difference in the Hct was also observed between the two groups: the mean Hct in the ACEI group was 28.7 +/- 2.9% while that in the non-ACEI group was 31.1 +/- 3.7%. The plasma Epo concentrations were significantly lower in the ACEI group than in the non-ACEI group. No significant differences in the rHuEpo dose and Hct were observed between the three ACE genotype classes in either the ACEI or the non-ACEI group, however, there was a significant difference among the three genotypes in the non-ACEI group in regard to the plasma Epo concentrations; patients with the DD genotype had higher concentrations than those with the DI or II genotypes. These data suggest that anemia in maintenance hemodialysis patients is worsened by ACEIs as a result of the suppression of Epo production. Although it has been suggested that the endogenous Epo concentrations in maintenance hemodialysis patients are associated with ACE gene polymorphism, no significant influence of the ACE genotype on the rHuEpo dose or Hct was evident. Therefore, it is possible that exacerbation of anemia by ACEIs in the patients receiving rHuEpo is a result of an inhibited bone marrow response to Epo.