Association between serum ferritin levels and clinical outcomes in maintenance hemodialysis patients: A retrospective single-center cohort study

Abstract

Background: Ferritin is a well-known marker of iron deficiency anemia, but the target in maintenance hemodialysis (MHD) patients remains controversial. This study examined the association between baseline ferritin levels and clinical outcomes. Methods: We retrospectively collected the data of outpatients on MHD for 5 years at St. Luke's International Hospital from July 2009. Patients with baseline ferritin levels of > 100 ng/mL in June 2009 were defined as the high-ferritin (HF) group and the remaining patients as the low-ferritin (LF) group. The primary endpoint was all-cause mortality. The secondary endpoints included cardiovascular events and infection-related hospitalizations. Log-rank test and Cox proportional hazard analysis were performed. Results: Of 116 patients (age, 65.4 ± 13.4 years, 70% males), 29 (25%) and 87 (75%) belonged to the HF and LF groups, respectively. During the follow-up period of 1825 (interquartile range 819-1825) days, 38 patients (23 in the HF and 15 in the LF groups) died. According to the Kaplan-Meier survival curves, the HF group had significantly poor survival compared with the LF group (p = 0.0089). After adjusting for age, sex, vintage of hemodialysis, C-reactive protein levels, and history of cardiovascular events, the hazard ratio (HR) for the HF group was 2.49 (95% confidence interval (CI), 1.21-5.12). The multivariate analysis of cardiovascular events revealed a similar result with statistical significance (HR 2.69; 95% CI 1.12-6.46). Infection-related hospitalizations did not exhibit any statistically significant difference. Conclusions: In MHD patients, ferritin levels > 100 ng/mL is associated with increased rates of all-cause mortality and cardiovascular events.