Association of whole blood essential metals with neurodevelopment among preschool children.

Background: Essential metals may play roles in neurodevelopment. The aim was to evaluate the associations of magnesium (Mg), iron (Fe), copper (Cu), and zinc (Zn) levels with neurodevelopment among preschool children.

Methods: The medical records of eligible children enrolled between January 2019 and July 2022 were retrospectively reviewed for required information. The quantitative measurement of metals was conducted using atomic absorption spectroscopy, while screening of neurodevelopment was performed using the Ages and Stages Questionnaire. Modified Poisson regression and Bayesian kernel machine regression (BKMR) analyses were used to evaluate the prevalence ratio (PR) of their independent and joint associations.

Results: 662 (14.8%) children were found to have possible neurodevelopmental delays. Modified Poisson regression showed that Mg, Cu, and Zn levels were independently and negatively associated with the risk of neurodevelopmental delay. The PRs (95% CIs) for per log₂ increment of the above metals were 0.35 (0.19-0.62), 0.57 (0.42-0.77), and 0.63 (0.42-0.96). These negative associations were more pronounced in the gross motor and personal-social domains while considering the concrete five domains. BKMR showed a negative association of metal mixture with the risk of neurodevelopmental delay.

Conclusion: Mg, Cu, and Zn were inversely associated with neurodevelopmental delay. Sufficient essential metal levels are important for neurodevelopment.

Impact: Essential metals play a key role in neurodevelopment. The association of essential metal mixture with neurodevelopment is relatively scarce. Preschool children with possible neurodevelopmental delay are found to have lower Mg, Cu, and Zn levels than their counterparts. Single Mg, Cu, Zn levels, and elevated essential metal mixture are negatively associated with the risk of possible neurodevelopmental delay.