title: Impact of prenatal exposure to cadmium on cognitive development at preschool age and the importance of selenium and iodine.
abstract: The evidence regarding a potential link of low-to-moderate iodine deficiency, selenium status, and cadmium exposure during pregnancy with neurodevelopment is either contradicting or limited. We aimed to assess the prenatal impact of cadmium, selenium, and iodine on children's neurodevelopment at 4 years of age. The study included 575 mother-child pairs from the prospective "Rhea" cohort on Crete, Greece. Exposure to cadmium, selenium and iodine was assessed by concentrations in the mother's urine during pregnancy (median 13 weeks), measured by ICPMS. The McCarthy Scales of Children's Abilities was used to assess children's general cognitive score and seven different sub-scales. In multivariable-adjusted regression analysis, elevated urinary cadmium concentrations (≥0.8 µg/L) were inversely associated with children's general cognitive score [mean change: -6.1 points (95 % CI -12; -0.33) per doubling of urinary cadmium; corresponding to ~0.4 SD]. Stratifying by smoking status (p for interaction 0.014), the association was restricted to smokers. Urinary selenium was positively associated with children's general cognitive score [mean change: 2.2 points (95 % CI -0.38; 4.8) per doubling of urinary selenium; ~0.1 SD], although the association was not statistically significant. Urinary iodine (median 172 µg/L) was not associated with children's general cognitive score. In conclusion, elevated cadmium exposure in pregnancy of smoking women was inversely associated with the children's cognitive function at pre-school age. The results indicate that cadmium may adversely affect neurodevelopment at doses commonly found in smokers, or that there is an interaction with other toxicants in tobacco smoke. Additionally, possible residual confounding cannot be ruled out.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, 171 77, Stockholm, Sweden. Maria.Kippler@ki.se.
authors.forename: Maria
authors.initials: M
authors.lastname: Kippler
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, 171 77, Stockholm, Sweden.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bottai
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Vaggelis
authors.initials: V
authors.lastname: Georgiou
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Katerina
authors.initials: K
authors.lastname: Koutra
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Chalkiadaki
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Mariza
authors.initials: M
authors.lastname: Kampouri
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Andriani
authors.initials: A
authors.lastname: Kyriklaki
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Marina
authors.initials: M
authors.lastname: Vafeiadi
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Fthenou
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Vassilaki
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), 08003, Barcelona, Spain.|Municipal Institute of Medical Research (IMIM-Hospital del Mar), 08003, Barcelona, Spain.|National School of Public Health, 11521, Athens, Greece.
authors.forename: Manolis
authors.initials: M
authors.lastname: Kogevinas
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, 171 77, Stockholm, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Vahter
authors.affiliation: Department of Social Medicine, Faculty of Medicine, University of Crete, 71003, Heraklion, Crete, Greece.|Department of Genetics and Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 40, PO Box 616, 6229 ER, Maastricht, The Netherlands.
authors.forename: Leda
authors.initials: L
authors.lastname: Chatzi
mesh_terms: D000328:Adult; D002104:Cadmium / Q000652:urine*; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D003072:Cognition Disorders / Q000139:chemically induced* / Q000652:urine; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007455:Iodine / Q000652:urine*; D008137:Longitudinal Studies; D008297:Male; D009035:Mothers; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D011446:Prospective Studies; D012643:Selenium / Q000652:urine*; D055815:Young Adult
chemical_list: D002104:Cadmium; D007455:Iodine; D012643:Selenium
keywords: Cadmium; Cognitive development; Iodine; Prenatal exposure; Selenium; Urine