ArticleJournal of neurodevelopmental disorders2020
Stunting and lead: using causal mediation analysis to better understand how environmental lead exposure affects cognitive outcomes in children.
Article in Journal of neurodevelopmental disorders, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
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Who cites it
6 citing papers in PubMed, 1 synthesis or guideline pooled it, 17 citations in OpenAlex.
- Heavy metals and neurodevelopment of children in low and middle-income countries: A systematic review.PloS one · 2022Pooled it
- Association Between Exposure to Multiple Toxic Metals in Follicular Fluid and the Risk of PCOS Among Infertile Women: The Mediating Effect of Metabolic Markers.Biological trace element research · 2025Article
- Diet quality and blood lead levels in Uruguayan first graders.The Science of the total environment · 2024Article
- Secular trends in blood lead concentrations of school-age children in Montevideo, Uruguay from 2009 to 2019.Environmental pollution (Barking, Essex : 1987) · 2024Article
- Lead Exposure Can Affect Early Childhood Development and Could Be Aggravated by Stunted Growth: Perspectives from Mexico.International journal of environmental research and public health · 2023Article
- Umbilical cord serum elementomics of 52 trace elements and early childhood neurodevelopment: Evidence from a prospective birth cohort in rural Bangladesh.Environment international · 2022Article
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Authors and funding
11 authors at 6 institutions in 2 countries.
Funding
Abstract
backgroundMany children in Bangladesh experience poor nutritional status and environmental lead exposure, both of which are associated with lower scores on neurodevelopmental assessments. Recent studies have suggested that part of lead's adverse effects on neurodevelopment are caused in part by lead's effect on growth. New statistical methods are now available to evaluate potential causal pathways in observational studies. This study used a novel statistical method to test the hypothesis that stunting, a measure of linear growth related to poor nutrition, is a mediator and/or an effect modifier of the lead exposure's adverse effect on cognitive development.
methodsParticipants were 734 children from a longitudinal birth cohort established in rural Bangladesh to study the health effects of prenatal and early childhood environmental metal exposures. Lead exposure was estimated using umbilical cord blood samples obtained at birth and blood obtained via venipuncture at age 20-40 months. Stunting was determined using the World Health Organization's standards. Neurodevelopment was assessed at age 20-40 months years using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). We evaluated the effect of lead on stunting and whether the effect of lead on cognitive scores is modified by stunting status in multivariable regression analyses. We then conducted a novel 4-way mediation analysis that allows for exposure-mediator interaction to assess how much of the effect of lead on cognitive scores is explained by the pathway through stunting (mediation) and how much is explained by the interaction between lead and stunt (effect modification).
resultsStunting was not a mediator of the effect of lead in our analyses. Results suggested effect modification by stunting. In an area of Bangladesh with lower lead exposures (median umbilical cord blood lead concentration, 1.7 μg/dL), stunting modified the relationship between prenatal blood lead concentrations and cognitive score at age 2-3 years. A 1-unit increase in natural log cord blood lead concentration in the presence of stunting was associated with a 2.1-unit decrease in cognitive scores (β = - 2.10, SE = 0.71, P = 0.003). This interaction was not found in a second study site where lead exposures were higher (median umbilical cord blood lead concentration, 6.1 μg/dL, β = - 0.45, SE = 0.49, P = 0.360).
conclusionsWe used a novel method of mediation analysis to test whether stunting mediated the adverse effect of prenatal lead exposure on cognitive outcomes in Bangladesh. While we did not find that stunting acted as mediator of lead's effect on cognitive development, we found significant effect modification by stunting. Our results suggest that children with stunting are more vulnerable to the adverse effects of low-level lead exposure.
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