Chronic Iron Deficiency and Cognitive Function in Early Childhood

Time to Resolution of Severe Anemia in Young Children With Iron Deficiency

Iron deficiency anemia in children remains a pervasive problem. Prolonged iron deficiency anemia (IDA) is linked to adverse neurodevelopmental outcomes, but the duration of severe IDA (hemoglobin <7 g/dL) in children is poorly studied, particularly for racial/ethnic minority groups. We reviewed the electronic medical records of 92 children (1 to 5 y old) with IDA within a major metropolitan health care system. Duration of anemia, hemoglobin at diagnosis and nadir, age, sex, race/ethnicity, and the use of intravenous interventions were analyzed by Kaplan-Meier curves, Cox regression, and logistic regression. The majority of the included children were Asian (72.8%). Anemia resolution was documented in 68% of cases, and 47% of cases received intravenous intervention. Iron repletion was only confirmed in 37% of cases (n=34), leaving many children with unclear resolution at risk for recurrence. Caucasian children had anemia resolution faster than Black or Asian children, and the latter groups were also less likely to reach hemoglobin normalization. Children with intravenous interventions were more likely to have documented resolution than those with only oral treatment. Those receiving intravenous interventions were more likely to be followed through anemia resolution, although treatment standardization was lacking, and confirmation of iron storage repletion was rarely checked. Future studies should emphasize the importance of ensuring iron storage replacement and potentially utilize time-to-anemia resolution data to determine optimal hemoglobin values for intravenous iron as a first-line intervention.

Impact of Nutritional Minerals Biomarkers on Cognitive Performance Among Bangladeshi Rural Adolescents-A Pilot Study

Background: Nutritional metals (NM) are essential for neurodevelopment and cognitive performance during growth. Nevertheless, epidemiological evidence regarding the associations between NM and brain function remains understudied, particularly among adolescents. Therefore, the objective of this pilot study was to examine the effects of NM biomarkers such as iron (Fe), selenium (Se), zinc (Zn), magnesium (Mg), and copper (Cu) on neurobehavioral functions among a group of rural Bangladeshi adolescents. Methodology: We conducted a cross-sectional study involving 105 adolescents aged 13-17 from Araihazar, Bangladesh. Cognitive function was assessed using the computer-based Behavioral Assessment and Research System (BARS), focusing attention, memory, and executive function, and blood NM levels (Fe, Se, Zn, Mg, and Cu) were measured. Associations between individual minerals, NM composite scores, and cognition were analyzed using multiple linear regressions. Results: This study included 47 boys and 58 girls with an average age of 15 years. Fe levels were correlated with Continuous Performance Test (CPT) latency (r = -0.42, p < 0.05) and Se levels correlated with Match-to-Sample (MTS) correct count (r = 0.32, p < 0.01). Linear regressions showed that Se was associated with MTS correct count (b = 0.02, 95%CI: 0.01, -0.04), reflecting visual memory, and Fe was associated with CPT latency (b = -0.68, 95%CI: -1.11, -0.26), reflecting improved attention. The same BARS measures were also significantly associated with the 3-NM composite score. Conclusions: Our findings suggest that NM, particularly Fe, Se, and NM mixtures, could play a crucial role in brain development and neurocognitive function during adolescence. Further studies will help design national public health policies and strategies to address and mitigate brain health deficiencies among adolescents.

Dietary iron intake has long-term effects on the fecal metabolome and microbiome

Iron is essential for life, but its imbalances can lead to severe health implications. Iron deficiency is the most common nutrient disorder worldwide, and iron dysregulation in early life has been found to cause long-lasting behavioral, cognitive, and neural effects. However, little is known about the effects of dietary iron on gut microbiome function and metabolism. In this study, we sought to investigate the impact of dietary iron on the fecal metabolome and microbiome by using mice fed with three diets with different iron content: an iron deficient, an iron sufficient (standard), and an iron overload diet for 7 weeks. Additionally, we sought to understand whether any observed changes would persist past the 7-week period of diet intervention. To assess this, all feeding groups were switched to a standard diet, and this feeding continued for an additional 7 weeks. Analysis of the fecal metabolome revealed that iron overload and deficiency significantly alter levels of peptides, nucleic acids, and lipids, including di- and tri-peptides containing branched-chain amino acids, inosine and guanosine, and several microbial conjugated bile acids. The observed changes in the fecal metabolome persist long after the switch back to a standard diet, with the cecal gut microbiota composition and function of each group distinct after the 7-week standard diet wash-out. Our results highlight the enduring metabolic consequences of nutritional imbalances, mediated by both the host and gut microbiome, which persist after returning to the original standard diets.

Recommendations for diagnosis, treatment, and prevention of iron deficiency and iron deficiency anemia

Iron is an essential nutrient and a constituent of ferroproteins and enzymes crucial for human life. Generally, nonmenstruating individuals preserve iron very efficiently, losing less than 0.1% of their body iron content each day, an amount that is replaced through dietary iron absorption. Most of the iron is in the hemoglobin (Hb) of red blood cells (RBCs); thus, blood loss is the most common cause of acute iron depletion and anemia worldwide, and reduced hemoglobin synthesis and anemia are the most common consequences of low plasma iron concentrations. The term iron deficiency (ID) refers to the reduction of total body iron stores due to impaired nutrition, reduced absorption secondary to gastrointestinal conditions, increased blood loss, and increased needs as in pregnancy. Iron deficiency anemia (IDA) is defined as low Hb or hematocrit associated with microcytic and hypochromic erythrocytes and low RBC count due to iron deficiency. IDA most commonly affects women of reproductive age, the developing fetus, children, patients with chronic and inflammatory diseases, and the elderly. IDA is the most frequent hematological disorder in children, with an incidence in industrialized countries of 20.1% between 0 and 4 years of age and 5.9% between 5 and 14 years (39% and 48.1% in developing countries). The diagnosis, management, and treatment of patients with ID and IDA change depending on age and gender and during pregnancy. We herein summarize what is known about the diagnosis, treatment, and prevention of ID and IDA and formulate a specific set of recommendations on this topic.

Hemoglobin Threshold for Blood Transfusion in Young Children Hospitalized with Iron Deficiency Anemia

Current recommendations advise against blood transfusion in hemodynamically stable children with iron deficiency anemia. In an observational study of 125 children aged 6 through 36 months, hospitalized with iron deficiency anemia, we found that hemoglobin level predicted red blood cell transfusion (area under the curve 0.8862). A hemoglobin of 39 g/L had sensitivity 92% and specificity 72% for transfusion.

Development of Iron Status Measures during Youth: Associations with Sex, Neighborhood Socioeconomic Status, Cognitive Performance, and Brain Structure

BACKGROUND

Iron is essential to brain function, and iron deficiency during youth may adversely impact neurodevelopment. Understanding the developmental time course of iron status and its association with neurocognitive functioning is important for identifying windows for intervention.

OBJECTIVES

This study aimed to characterize developmental change in iron status and understand its association with cognitive performance and brain structure during adolescence using data from a large pediatric health network.

METHODS

This study included a cross-sectional sample of 4899 participants (2178 males; aged 8-22 y at the time of participation, M [SD] = 14.24 [3.7]) who were recruited from the Children's Hospital of Philadelphia network. Prospectively collected research data were enriched with electronic medical record data that included hematological measures related to iron status, including serum hemoglobin, ferritin, and transferrin (33,015 total samples). At the time of participation, cognitive performance was assessed using the Penn Computerized Neurocognitive Battery, and brain white matter integrity was assessed using diffusion-weighted MRI in a subset of individuals.

RESULTS

Developmental trajectories were characterized for all metrics and revealed that sex differences emerged after menarche such that females had reduced iron status relative to males [all R2partial > 0.008; all false discovery rates (FDRs) < 0.05]. Higher socioeconomic status was associated with higher hemoglobin concentrations throughout development (R2partial = 0.005; FDR < 0.001), and the association was greatest during adolescence. Higher hemoglobin concentrations were associated with better cognitive performance during adolescence (R2partial = 0.02; FDR < 0.001) and mediated the association between sex and cognition (mediation effect = -0.107; 95% CI: -0.191, -0.02). Higher hemoglobin concentration was also associated with greater brain white matter integrity in the neuroimaging subsample (R2partial = 0.06, FDR = 0.028).

CONCLUSIONS

Iron status evolves during youth and is lowest in females and individuals of low socioeconomic status during adolescence. Diminished iron status during adolescence has consequences for neurocognition, suggesting that this critical period of neurodevelopment may be an important window for intervention that has the potential to reduce health disparities in at-risk populations.