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.