Iron-deficiency anemia in infancy and poorer cognitive inhibitory control at age 10 years

Abstract

AIM The aim of this study was to assess the effects of iron-deficiency anemia (IDA) in infancy on executive functioning at age 10 years, specifically inhibitory control on the Go/No-Go task. We predicted that children who had IDA in infancy would show poorer inhibitory control. METHOD We assessed cognitive inhibitory control in 132 Chilean children (mean [SD] age 10y [1mo]): 69 children had IDA in infancy (45 males, 24 females) and 63 comparison children who did not have IDA (26 males, 37 females). Participants performed the Go/No-Go task with event-related potentials. Group differences in behavioral (accuracy, reaction time) and electrophysiological outcomes (N2 and P300 components) were analyzed using repeatedmeasures analyses of variance. N2 and P300 are interpreted to reflect attention and resource allocation respectively. RESULTS Relative to comparison participants, children who had IDA in infancy showed slower reaction time (mean [SE], 528.7ms [14.2] vs 485.0ms [15.0], 95% confidence interval [CI] for difference between groups 0.9–86.5); lower accuracy (95.4% [0.5] vs 96.9% [0.6], 95% CI 3.0 to 0.1); longer latency to N2 peak (378.9ms [4.9] vs 356.9ms [5.0], 95% CI 7.5–36.6); and smaller P300 amplitude (4.5lV [0.8] vs 7.6lV [0.9], 95% CI 5.5 to 0.5). INTERPRETATION IDA in infancy was associated with slower reaction times and poorer inhibitory control 8 to 9 years after iron therapy. These findings are consistent with the long-lasting effects of early IDA on myelination and/or prefrontal–striatal circuits where dopamine is the major neurotransmitter.