Iron deficiency associates with deterioration in several symptoms independently from hemoglobin level among chronic hemodialysis patients

BACKGROUND: While iron deficiency (ID) is a frequent cause of anemia in hemodialysis patients, the clinical impact of ID without anemic level of hemoglobin remains unclear. As such, this study was designed to clarify the manifestations of ID itself in subjects on hemodialysis. METHODS: Maintenance hemodialysis patients achieving target hemoglobin levels (≥ 10.0g/dL) under treatment in our clinic were stratified for comparison from three perspectives: ID (transferrin saturation [TSAT] < 20% or ferritin < 100ng/mL) vs non-ID, level of TSAT (< or ≥ 20%), and level of serum ferritin concentration (< or ≥ 100ng/mL). The severity of frequent symptoms was determined by a self-rating symptom score questionnaire, and the rate of those with severe manifestations was calculated for each symptom. Significant difference was examined between groups; univariate and adjusted multivariate odds ratios and 95% confidence intervals were obtained by logistic regression. RESULTS: Among 154 subjects selected for analysis, the ratio of severe arthralgia and fatigue was significantly higher in the ID group (n = 94) compared to the non-ID group (n = 60), in both univariate and adjusted multivariate analyses. Moreover, in multivariate analysis, low TSAT was significantly associated with exacerbation of pain during vascular access puncture and intradialytic leg cramps, while low serum ferritin concentration was related to significant increase in severe arthralgia, fatigue, intradialytic headache and leg cramps. CONCLUSIONS: ID was identified as a risk factor regarding severity of several symptoms even without low hemoglobin level among chronic hemodialysis patients, and supplementation of iron was considered efficacious for improving critical symptoms affecting those undergoing maintenance dialysis.