Infant iron deficiency, iron supplementation, and psychosocial stress as predictors of neurocognitive development in Chilean adolescents

ABSTRACT

Objective: The aim of the current study was to examine the unique and joint contributions of iron deficiency, iron supplementation, and psychosocial stress in infancy and stress in adolescence to neurocognitive functioning in adolescence.

Methods: The current study (N = 796; M_age = 14.4y) involved a prospective cohort of low- and middle-socioeconomic status adolescents in Santiago, Chile. As infants, they had participated in an iron supplementation trial. Infant iron status was assessed at 12–18 months, and mothers answered questions about family psychosocial stress at 6–12 months and in adolescence (maternal depressive symptoms, home support for child development, stressful life events, father absence, socioeconomic status, and parental education). Neurocognitive functioning was assessed in adolescence using the Balloon Analogue Risk Task, Stockings of Cambridge, Trail Making Test, Purdue Pegboard Test, and Wisconsin Card Sorting Test.

Results: Greater psychosocial stress in infancy predicted less risk-taking, poorer planning abilities and fluid cognition, and slower processing speed in adolescence. Iron deficiency anemia in infancy predicted less risk-taking. Greater adolescent psychosocial stress predicted difficulties in set-shifting. There were no interactions between infant psychosocial stress and iron deficiency predicting adolescent neurocognitive functioning.

Conclusion: These results suggest that interventions to reduce infant psychosocial stress may be more likely to prevent multiple neurocognitive deficits in adolescence than interventions to reduce infant iron deficiency.

KEYWORDS:

• Stress
• iron deficiency
• infancy
• adolescence
• neurocognitive functioning
• maternal depression
• socioeconomic status
• child development

Acknowledgements

We would like to thank our deceased dear colleague and friend Marcela Castillo for her enormous contributions developing and maintaining this longitudinal study from its inception. This work was made possible by funding from F32HD088029 (PI: Doom), R01HD14122 (PI: Lozoff), and R01HD33487 (PI: Lozoff & Gahagan). The sponsors had no role in the study design, the collection, analysis, or interpretation of data, the writing of the report, or the decision to submit the manuscript for publication.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data sharing

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Additional information

Funding

This work was supported by Eunice Kennedy Shriver National Institute of Child Health and Human Development [grant number R01HD14122]; Eunice Kennedy Shriver National Institute of Child Health and Human Development [grant number R01HD33487]; Eunice Kennedy Shriver National Institute of Child Health and Human Development [grant number F32HD088029]; National Heart, Lung, and Blood Institute [grant number K01HL143159].

Notes on contributors

Jenalee R. Doom

Dr. Jenalee R. Doom is an assistant professor in the Department of Psychology and Stress, Early Experiences, and Development (SEED) Research Center at the University of Denver.

Sheila Gahagan

Dr. Sheila Gahagan is a Chief of Academic General Pediatrics, and holds the Stein Chair in Developmental and Behavioral Pediatrics at the University of California, San Diego.

Gabriela Caballero

Gabriela Caballero is a psychologists at the Universidad de Chile.

Pamela Encina

Pamela Encina is a psychologists at the Universidad de Chile.

Betsy Lozoff

Dr. Betsy Lozoff is a Professor Emerita of Pediatrics at the University of Michigan.