Evidence that cognitive deficit in children is associated not only with iron deficiency, but also with blood lead concentration: A preliminary study

The present study investigated whether blood lead concentrations are elevated in iron-deficient children, and examined the association between iron deficiency and/or elevated blood lead concentration and cognitive deficits in children. This study is a component of the Mothers’ and Children’s Environmental Health (MOCEH) study, a multi-centre birth cohort project in Korea that began in 2006. The study cohort consisted of 194 children who underwent testing of blood lead and serum C-reactive proteins (CRPs) and ferritin concentrations, and the Korean version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R), at 60 months of age. In addition, the mothers’ blood lead concentrations during pregnancy were included in the analyses. Multivariate linear regression analysis was performed to analyse the correlation between high blood lead and low serum ferritin concentrations, after adjustment for covariates, in children, as well as to analyse the association of verbal IQ with serum ferritin and blood lead concentrations. Lead and ferritin concentrations were inversely and significantly associated in children after adjustment for covariates. Moreover, both concentrations were associated with verbal IQ, after adjustment for covariates, and each was associated with cognitive deficits after adjustment for the other. Sobel test statistics showed that blood lead concentration was a significant partial mediator for the relationship between iron deficiency and verbal IQ. Due to the results discussed in the present study, cognitive deficit in children seems to be associated not only with iron deficiency, but also with blood lead concentration.

Authors: Jeong KS, Park H, Ha E, Hong YC, Ha M, Park H, Kim BN, Lee SJ, Lee KY, Kim JH, Kim Y. ;Full Source: Journal of Trace Elements in Medicine and Biology. 2014 Sep 3. pii: S0946-672X(14)00168-0. doi: 10.1016/j.jtemb.2014.08.014. [Epub ahead of print] ;