Iron Indices and Mortality in Maintenance Hemodialysis Patients

Abstract

Background: The relationship between the iron indices and mortality in maintenance hemodialysis (MHD) patients has remained unclear. We performed a retrospective, observational cohort study to investigate the relationships between serum ferritin levels and mortality in MHD patients. Methods: MHD outpatients (n = 150) were followed up for a median period of 49 months. Their ESA and low-dose iron supplement dosages were adjusted to maintain their hemoglobin (Hb) concentrations in the 10 - 11 g/dl range in accordance with Japanese guidelines. The Kaplan-Meier method, log-rank tests, and Cox proportional hazards models were used to perform the statistical analyses. The patients were divided into 3 groups according to their serum ferritin levels: a serum ferritin < 50 ng/ml group; a 50 - 100 ng/ml group; and a > 100 ng/ml group. Results: During the median follow-up period of 49 months, there were 55 deaths. The multivariate analysis showed no significant associations between the ferritin level groups and all-cause mortality or cardiovascular (CV) events, and the Kaplan-Meier analysis showed no significant differences among the 3 ferritin level groups in all-cause mortality and CV event rates. However, the multivariate analysis revealed that age, CRP level and a history of previous CV disease were independently associated with all-cause mortality, while diabetes, previous CV disease, and iron administration were independently associated with CV events. Conclusion: The results of this study revealed no significant associations of MHD patients between the ferritin ranges and all-cause mortality or CV events. Thus, the adverse clinical outcomes in these patients were independently associated with other markers and not with their serum ferritin levels.