The Effect of High-Flux Hemodialysis on Hemoglobin Concentrations in Patients with CKD

Summary Background and objectives Hemodialysis treatment induces markers of inflammation and oxidative stress, which could affect hemoglobin levels and the response to erythropoietin use. This study sought to determine whether high-flux dialysis would help improve markers of renal anemia, inflammation, and oxidative stress compared with low-flux dialysis. Design, settings, participants, & measurements In a prospective, controlled study, 221 patients undergoing maintenance hemodialysis and receiving darbepoetin-alfa treatment (mean age, 66 years; 55% male) from 19 centers were screened in a 20-week run-in period of low-flux hemodialysis with a synthetic dialysis membrane. Thereafter, 166 patients were enrolled and randomly assigned to receive a synthetic high-flux membrane or to continue on low-flux dialysis for 52 weeks. Data on myeloperoxidase, oxidized LDL, high-sensitivity C-reactive protein, and the Malnutrition Inflammation Score were collected at baseline and after 52 weeks; routine laboratory data, such as hemoglobin, ferritin, and albumin, and the use of darbepoetin-alfa, were also measured in the run-in period. Results After 52 weeks, the low-flux and the high-flux groups did not differ with respect to hemoglobin (mean ± SD, 11.7±0.9 g/dl versus 11.7±1.1 g/dl; P =0.62) or use of darbepoetin-alfa (mean dosage ± SD, 29.8±24.8 μg/wk versus 26.0±31.1 μg/wk; P =0.85). Markers of inflammation, oxidative stress, or nutritional status also did not differ between groups. Conclusion Over 1 year, high-flux dialysis had no superior effects on hemoglobin levels or markers of inflammation, oxidative stress, and nutritional status. These data do not support the hypothesis that enhanced convective toxin removal would improve patient outcome.