Effects of Daily Iron Supplementation on Motor Development and Brain Connectivity in Preterm Infants: A Diffusion Magnetic Resonance Study.

Mingyan Li,Weijun Chen,Chai Ji,Yuqing You,Tingting Liu,Ying Lv,Jie Shao,Fusheng Gao,Quan Zheng,Weifeng Xuan

doi:10.3389/fnins.2021.769558

Abstract

Objectives: The aim of the study is to demonstrate the characteristic of motor development and MRI changes of related brain regions in preterm infants with different iron statuses and to determine whether the daily iron supplementation can promote motor development for preterm in early infancy.Methods: The 63 preterm infants were grouped into non-anemia with higher serum ferritin (NA-HF) group and anemia with lower serum ferritin (A-LF) group according to their lowest serum Hb level in the neonatal period as well as the sFer at 3 months old. Forty-nine participants underwent MRI scans and Infant Neurological International Battery (INFANIB) at their 3 months. At 6 months of corrected age, these infants received the assessment of Peabody Developmental Motor Scales (PDMS) after 2 mg/kg/day iron supplementation.Results: In total, 19 preterm infants were assigned to the NA-HF group while 44 preterm infants to the A-LF groups. The serum ferritin (sFer) level of the infants in A-LF group was lower than that in NA-HF group (44.0 ± 2.8 mg/L vs. 65.1 ± 2.8 mg/L, p < 0.05) and was with poorer scores of INFANIB (66.8 ± 0.9 vs. 64.4 ± 0.6, p < 0.05) at 3 months old. The structural connectivity between cerebellum and ipsilateral thalamus in the NA-HF group was significantly stronger than that in the A-LF group (n = 17, 109.76 ± 23.8 vs. n = 32, 70.4 ± 6.6, p < 0.05). The decreased brain structural connectivity was positively associated with the scores of PDMS (r = 0.347, p < 0.05). After 6 months of routine iron supplementation, no difference in Hb, MCV, MCHC, RDW, and sFer was detected between A-LF and NA-HF groups as well as the motor scores of PDMS-2 assessments.Conclusion: Iron status at early postnatal period of preterm infant is related to motor development and the enrichment of brain structural connectivity. The decrease in brain structural connectivity is related to the motor delay. After supplying 2 mg/kg of iron per day for 6 months, the differences in the iron status and motor ability between the A-LF and NA-HF groups were eliminated.

Highlights

Iron deficiency (ID) continues to be the most prevalent nutrient deficiency in the world
gestational age (GA) and birth weight were lower in the A-LF group than in the NA-HF group
There was no significant difference of Hb between the A-LF and NA-HF groups at 3 months old (n = 44, Hb: 102.1 ± 1.3 mg/L vs. n = 19, Hb: 97.6 ± 2.7 g/L, p = 0.127), serum ferritin (sFer) of the A-LF group was lower than that of the NA-HF group (n = 44, sFer: 44.0 ± 2.8 mg/L vs. n = 19, sFer: 65.1 ± 2.8 mg/L, p < 0.05) (Table 2)

Summary

Introduction

Iron deficiency (ID) continues to be the most prevalent nutrient deficiency in the world. Iron is an essential mineral necessary for delivering oxygen to tissues throughout the body as well as serving important roles in metabolism, respiration, and immune functions (Todorich et al, 2009). It is a cofactor in the central nervous system development processes (DellaValle, 2013). The IDA stage is symbolized by lower sFer and hemoglobin and by lower mean corpuscular volume (MCV), lower mean hemoglobin concentration (MCHC), and higher red blood cell distribution width (RDW)

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Conclusion