Effects of iron supplementation on neural indices of habituation in Bangladeshi children.
Study Goal
The researchers aimed to determine whether iron supplementation improves neural indices of habituation in children with high anemia prevalence.
Results Summary
The study found no significant effects of iron supplementation (iron syrup or MNPs) on neural habituation indices, despite improvements in hemoglobin and ferritin levels. No differences were observed in primary or secondary outcomes at 3 or 12 months.
Population
8-month-old children in Bangladesh with >40% anemia prevalence.
Effective Dosage
12.5 mg iron daily (as iron syrup or in MNPs).
Duration
3 months of intervention, with follow-up at 12 months.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
iron syrup | no change | amplitude of the mismatch response | children | mean difference (MD) = 0.07μV [95% CI: -1.22, 1.37] | no treatment effects | #1 |
multiple micronutrient powders (MNPs) | no change | amplitude of the mismatch response | children | MD = 0.58μV [95% CI: -0.74, 1.90] | no treatment effects | #2 |
iron syrup | no change | secondary ERP outcomes | children | - | no treatment effects | #3 |
multiple micronutrient powders (MNPs) | no change | secondary ERP outcomes | children | - | no treatment effects | #4 |
iron syrup | increase | hemoglobin concentrations | children | - | improvements | #5 |
iron syrup | increase | ferritin concentrations | children | - | improvements | #6 |
multiple micronutrient powders (MNPs) | increase | hemoglobin concentrations | children | - | improvements | #7 |
multiple micronutrient powders (MNPs) | increase | ferritin concentrations | children | - | improvements | #8 |
iron interventions | no change | neural indices of habituation | Bangladeshi children with >40% anemia prevalence | - | insufficient to improve | #9 |
MNP interventions | no change | neural indices of habituation | Bangladeshi children with >40% anemia prevalence | - | insufficient to improve | #10 |
BACKGROUND: Iron deficiency and anemia have been associated with poor cognition in children, yet the effects of iron supplementation on neurocognition remain unclear. OBJECTIVE: We aimed to examine the effects of supplementation with iron on neural indices of habituation using auditory event-related brain potentials (ERPs). METHODS: This substudy was nested within a 3-arm, double-blind, double-dummy, individual randomized trial in Bangladesh, in which 3300 8-mo-old children were randomly selected to receive 3 mo of daily iron syrup (12.5 mg iron), multiple micronutrient powders (MNPs) (including 12.5 mg iron), or placebo. Children were assessed after 3 mo of intervention (mo 3) and 9 mo thereafter (mo 12). The neurocognitive substudy comprised a randomly selected subset of children from the main trial. Brain activity elicited during an auditory roving oddball task was recorded using electroencephalography to provide an index of habituation. The differential response to a novel (deviant) compared with a repeated (standard) sound was examined. The primary outcome was the amplitude of the mismatch response (deviant minusstandard tone waveforms) at mo 3. Secondary outcomes included the deviant and standard tone-evoked amplitudes, N2 amplitude differences, and differences in mean amplitudes evoked by deviant tones presented in the second compared with first half of the oddball sequence at mo 3 and 12. RESULTS: Data were analyzed from 329 children at month 3 and 363 at mo 12. Analyses indicated no treatment effects of iron interventions compared with placebo on the amplitude of the mismatch response (iron syrup compared with placebo: mean difference (MD) = 0.07μV [95% CI: -1.22, 1.37]; MNPs compared with placebo: MD = 0.58μV [95% CI: -0.74, 1.90]) nor any secondary ERP outcomes at mo 3 or 12, despite improvements in hemoglobin and ferritin concentrations from iron syrup and MNPs in this nested substudy. CONCLUSION: In Bangladeshi children with >40% anemia prevalence, iron or MNP interventions alone are insufficient to improve neural indices of habituation. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12617000660381.