ANEMIA IN HEMODIALYSIS-PATIENTS - VARIABLES AFFECTING THIS OUTCOME PREDICTOR

Despite the prevalent use of recombinant human erythropoietin (rhEPO), anemia is a frequent finding in hemodialysis patients. The goal of th is study was to evaluate the impact of anemia on patient survival and characterize the determinants of hematopoiesis that may be amenable to therapeutic manipulation to enhance rhEPO responsiveness and reduce d eath risk. Patient characteristics and laboratory data were collected for 21,899 patients receiving hemodialysis three times per week in dia lysis centers throughout the United States in 1993. Hemoglobin concent rations (Hb) less than or equal to 80 g/L were associated with a twofo ld increase in the odds of death (odds ratio = 2.01; P = 0.001) when c ompared with Hb 100 to 110 g/L. No improvement in the odds of death wa s afforded for Hb >110 g/L. Using multiple linear regression, variable s of rhEPO administration (rhEPO dose and percentage of treatments tha t rhEPO was administered), variables of iron status (serum iron, trans ferrin saturation, and ferritin), variables of nutritional status (ser um albumin and creatinine concentration), and the dose of dialysis (ur ea reduction ratio) were found to be significantly associated with hem oglobin concentration (P < 0.001). Age, race, and gender were also fou nd to be significantly associated with hemoglobin concentrations (P < 0.001). From this report, the following conclusions may be made. (I) A nemia may be predictive of an increased risk of mortality in some hemo dialysis patients. (2) Hemoglobin concentrations >110 g/L are not asso ciated with further improvements in the odds of death. (3) Laboratory surrogates of iron stores, nutritional status, and the delivered dose of dialysis are predictive of hemoglobin concentration. Whether manipu lation of the factors that improve anemia will also enhance the surviv al of patients on hemodialysis is unknown and should be evaluated by p rospective, interventional studies.