Factors contributing to higher hematocrit levels in hemodialysis patients not receiving recombinant human erythropoietin

Recombinant human erythropoietin (rHuEPO) is used to correct anemia in the majority of hemodialysis patients, but a few patients can maintain greater hematocrits without the use of rHuEPO. We aim to investigate which factors stimulate erythropoiesis, other than rHuEPO, in hemodialysis patients. One hundred fifty-eight patients undergoing regular hemodialysis treatment participated in a cross-sectional study. To keep the target hematocrit of 30%, 133 patients (84%) were administered rHuEPO, but 25 patients (16%) did not need rHuEPO. Mean hematocrits were 33.4% +/- 4.6% in patients who did not need rHuEPO and 30.9% +/- 4.0% in those administered rHuEPO. In the analysis of factors contributing to the lack of requirement of rHuEPO with multivariate logistic regression analysis, years on dialysis therapy and body mass index (BMI) were determined to be independent factors with odds ratios of 1.12 (95% confidence interval [CI], 1.02 to 1.23; P = 0.02) and 1.36 (95% CI, 1.13 to 1.63; P = 0.001), respectively. Neither serum erythropoietin level, albumin concentration, nor normalized protein catabolic rate contributed to the lack of requirement of rHuEPO. BMI correlated closely with log serum leptin level (r = 0.55; P < 0.0001), and log serum leptin level correlated inversely with rHuEPO dose (r = -0.18; P = 0.03). These results indicate that 16% of hemodialysis patients could maintain greater hematocrits without the administration of rHuEPO, and independently contributing factors were greater BMI and more years on hemodialysis therapy. Regarding nutritional parameters, a relatively greater BMI, possibly through effects of greater leptin levels, may stimulate erythropoiesis in uremic patients even in the absence of sufficient erythropoietin production. (C) 2002 by the National Kidney Foundation, Inc.