title: Evidence that cognitive deficit in children is associated not only with iron deficiency, but also with blood lead concentration: a preliminary study.
abstract: OBJECTIVE
  To investigate whether blood lead concentrations are elevated in iron-deficient children, and to examine the association between iron deficiency and/or elevated blood lead concentration and cognitive deficits in children.
  
  
  METHODS
  The present study is a component of the Mothers' and Children's Environmental Health (MOCEH) study, a multi-center 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 analyze the correlation between high blood lead and low serum ferritin concentrations, after adjustment for covariates, in children, as well as to analyze the association of verbal IQ with serum ferritin and blood lead concentrations.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.affiliation: Department of Occupational and Environmental Medicine, Dongguk University College of Medicine, Dongguk University Ilsan Hospital, Goyang, Republic of Korea.
authors.forename: Kyoung Sook
authors.initials: KS
authors.lastname: Jeong
authors.affiliation: Department of Child and Family Welfare, University of Ulsan, Ulsan, Republic of Korea.
authors.forename: Hyewon
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Preventive Medicine, Ewha Medical Research Center, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
authors.forename: Eunhee
authors.initials: E
authors.lastname: Ha
authors.affiliation: Institute of Environmental Medicine, Medical Research Center, Seoul National University, Seoul, Republic of Korea.
authors.forename: Yun-Chul
authors.initials: YC
authors.lastname: Hong
authors.affiliation: Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan, Republic of Korea.
authors.forename: Mina
authors.initials: M
authors.lastname: Ha
authors.affiliation: Department of Preventive Medicine, Ewha Medical Research Center, School of Medicine, Ewha Womans University, Seoul, Republic of Korea.
authors.forename: Hyesook
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Psychiatry, College of Medicine, Seoul National University, Seoul, Republic of Korea.
authors.forename: Bung-Nyun
authors.initials: BN
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea.
authors.forename: Soo-Jeong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea.
authors.forename: Kyung Yeon
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea.
authors.forename: Ja Hyeong
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea. Electronic address: yanghokm@nuri.net.
authors.forename: Yangho
authors.initials: Y
authors.lastname: Kim
mesh_terms: D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D003072:Cognition Disorders / Q000097:blood*; D003710:Demography; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007361:Intelligence Tests; D000090463:Iron Deficiencies; D007854:Lead / Q000097:blood*; D016014:Linear Models; D008297:Male; D011247:Pregnancy
chemical_list: D007854:Lead; D002097:C-Reactive Protein; D005293:Ferritins
keywords: Blood lead; IQ; Serum ferritin; WPPSI-R