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.Electronic supplementary materialThe online version of this article (doi:10.1007/s10654-016-0151-9) contains supplementary material, which is available to authorized users.

Maternal selenium status and neuropsychological development in Spanish preschool children

“…However, other studies failed to find any significant association with these and other assessed aspects of neuropsychological development in children from Greece (Kippler et al, 2016), USA (Oken et al, 2016), Poland (Polanska et al, 2016) and Japan (Tatsuta et al, 2017). Se levels (mean ± standard deviation) observed in these studies were 23 ± 8.6 µg/L in maternal urine at the first trimester of pregnancy in Greece (Kippler et al, 2016), 205.6 ± 34.6 ng/mL in erythrocytes at mid-pregnancy in USA (Oken et al, 2016), and 66.3 ± 10.2 and 67.0 ± 9.6 ng/g (for boys and girls, respectively) in cord plasma in Japan (Tatsuta et al, 2017). Conversely, Saint-Amour et al (2006) observed that prenatal Se levels were associated with alterations in the visual evoked potentials of Inuit children (cord blood Se was 4.44 ± 2.08 µmol/L) (Saint-Amour et al, 2006).…”

“…Very few prospective studies have evaluated the relationship between Se status during pregnancy and child neuropsychological development among populations with intermediate Se levels and the results obtained have been heterogeneous. Thus, positive, negative and null effects on child neuropsychological development have been observed in relationship to prenatal Se levels (Amorós et al, 2018;Kippler et al, 2016;Oken et al, 2016;Polanska et al, 2016;Skröder et al, 2015;Yang et al, 2013) and, in addition, the shape of this association has scarcely been assessed.…”

Early-Life Selenium Status and Cognitive Function at 5 and 10 Years of Age in Bangladeshi Children

“…Quality control was performed by including commercial reference materials for urine [Seronorm™ Trace Elements Urine Blank OK4636, Seronorm™ Trace Elements Urine NO2525, Seronorm™ Trace Elements Urine 1011644, Seronorm™ Trace Elements Urine 1011645 and National Institute of Standards and Technology (NIST) Standard Reference Material® 2670a], and the results for these samples were in line with recommended values (see Table S1). We also measured concentrations of arsenic, cadmium, and lead in urine at both 5 and 10 y, and we measured concentrations of manganese in drinking water collected at the 10-y follow-up ( Kippler et al 2012 , 2016 ). All concentrations in urine were adjusted to the average specific gravity (1.012) to compensate for variations in dilution ( Nermell et al 2008 ).…”

Effects of Prenatal Exposure to Endocrine Disruptors and Toxic Metals on The Fetal Epigenome

“…As a result, Cd levels in cord blood are typically lower than maternal Cd levels [40]. Nevertheless, in utero Cd exposure has been linked to a range of adverse health effects, including impaired growth and neurodevelopment [41][42][43]. To date, one study has examined the relationship between global DNA methylation and prenatal Cd exposure.…”