Do Extremely Low Gestational Age Neonates Regulate Iron Absorption via Hepcidin?

OBJECTIVES: To evaluate whether extremely preterm infants regulate iron status via hepcidin. STUDY DESIGN: In this retrospective analysis of infants from the Preterm Epo Neuroprotection (PENUT) Trial, urine hepcidin (Uhep) normalized to creatinine (Uhep/UCr) was evaluated among infants randomized to erythropoietin (Epo) or placebo. RESULTS: The correlation (r) between Uhep/UCr and serum markers of iron status (ferritin and zinc protoporphyrin-to-heme ratio [ZnPP/H]) and iron dose was assessed. A total of 243 urine samples from 76 infants born at 24-276/7 weeks gestation were analyzed. The median Uhep/UCr concentration was 0.3, 1.3, 0.4, and 0.1 ng/mg at baseline, 2 weeks, 4 weeks, and 12 weeks, respectively, in placebo-treated infants. The median Uhep/UCr value in Epo-treated infants were not significantly different, with the exception of the value at the 2-week time point (median Uhep/UCr, 0.1 ng/mg; P < .001). A significant association was seen between Uhep/UCr and ferritin at 2 weeks (r = 0.63; P < .001) and at 4 weeks (r = 0.41; P = .01) and between Uhep/UCr and ZnPP/H at 2 weeks (r = -0.49; P = .002). CONCLUSIONS: Uhep/UCr values correlate with serum iron markers. Uhep/UCr values vary over time and are affected by treatment with Epo, suggesting that extremely preterm neonates can regulate hepcidin and therefore their iron status. Uhep is suppressed in extremely preterm neonates, particularly those treated with Epo.

Enteral Iron Supplementation in Infants Born Extremely Preterm and its Positive Correlation with Neurodevelopment; Post Hoc Analysis of the Preterm Erythropoietin Neuroprotection Trial Randomized Controlled Trial.

OBJECTIVES: To test whether an increased iron dose is associated with improved neurodevelopment as assessed by the Bayley Scales of Infant Development, third edition (BSID-III) among infants enrolled in the Preterm Erythropoietin (Epo) Neuroprotection Trial (PENUT). STUDY DESIGN: This is a post hoc analysis of a randomized trial that enrolled infants born at 24-28 completed weeks of gestation. All infants in PENUT who were assessed with BSID-III at 2 years were included in this study. The associations between enteral iron dose at 60 and 90 days and BSID-III component scores were evaluated using generalized estimating equations models adjusted for potential confounders. RESULTS: In total, 692 infants were analyzed (355 placebo, 337 Epo). Enteral iron supplementation ranged from 0 to 14.7 mg/kg/d (IQR 2.1-5.8 mg/kg/d) at day 60, with a mean of 3.6 mg/kg/d in infants treated with placebo and 4.8 mg/kg/d in infants treated with Epo. A significant positive association was seen between BSID-III cognitive scores and iron dose at 60 days, with an effect size of 0.77 BSID points per 50 mg/kg increase in cumulative iron dose (P = .03). Greater iron doses were associated with greater motor and language scores but did not reach statistical significance. Results at 90 days were not significant. The effect size in the infants treated with Epo compared with placebo was consistently greater. CONCLUSIONS: A positive association was seen between iron dose at 60 days and cognitive outcomes. Our results suggest that increased iron supplementation in infants born preterm, at the doses administered in the PENUT Trial, may have positive neurodevelopmental effects, particularly in infants treated with Epo. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01378273.