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Measured Prenatal and Estimated Postnatal Levels of Polychlorinated Biphenyls (PCBs) and ADHD-Related Behaviors in 8-Year-Old Children.

Verner MA, Hart JE, Sagiv SK, Bellinger DC, Altshul LM, Korrick SA - Environ. Health Perspect. (2015)

Bottom Line: We aimed to assess whether estimated serum PCB levels in infancy are associated with attention deficit/hyperactivity disorder (ADHD)-related behaviors at 8 years of age among children whose cord serum PCB levels were previously shown to be associated with ADHD-related behaviors.Cord serum PCB-153 levels (median, 38 ng/g lipids) were associated with ADHD-related behaviors, although statistical significance was observed with quantile regression models only at the 75th percentile.Measured prenatal and estimated postnatal levels of polychlorinated biphenyls (PCBs) and ADHD-related behaviors in 8-year-old children.

View Article: PubMed Central - PubMed

Affiliation: Channing Division of Network Medicine, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT

Background: Epidemiologic studies of postnatal PCB exposure and behavior have not reported consistent evidence of adverse associations, possibly because of challenges in exposure estimation. We previously developed a pharmacokinetic model to improve estimation of children's PCB exposure.

Objectives: We aimed to assess whether estimated serum PCB levels in infancy are associated with attention deficit/hyperactivity disorder (ADHD)-related behaviors at 8 years of age among children whose cord serum PCB levels were previously shown to be associated with ADHD-related behaviors.

Methods: We used a pharmacokinetic model to estimate monthly serum polychlorinated biphenyl (PCB)-153 levels in 441 infants (ages 1-12 months) based on parameters such as breastfeeding and cord serum PCB-153 levels. Behavior was evaluated at age 8 using the Conners' Rating Scale for Teachers (CRS-T). Associations between PCB-153 levels and ADHD-related CRS-T indices were assessed using multivariable quantile regression at the 50th and 75th percentiles of CRS-T scores, where higher percentiles reflect more adverse behaviors.

Results: Cord serum PCB-153 levels (median, 38 ng/g lipids) were associated with ADHD-related behaviors, although statistical significance was observed with quantile regression models only at the 75th percentile. Associations with postnatal exposure estimates were attenuated. For example, hyperactive-impulsive behavior scores at age 8 years were 0.9 points (95% CI: 0.2, 2.5), 0.5 points (95% CI: 0.3, 2.3), and 0.3 points (95% CI: -0.2, 1.5) higher in association with interquartile range increases in serum PCB-153 at birth, 2 months, and 12 months of age, respectively.

Conclusions: Associations between estimated postnatal PCB-153 exposures and ADHD-related behaviors at 8 years of age were weaker than associations with PCB-153 concentrations measured in cord serum at birth.

Citation: Verner MA, Hart JE, Sagiv SK, Bellinger DC, Altshul LM, Korrick SA. 2015. Measured prenatal and estimated postnatal levels of polychlorinated biphenyls (PCBs) and ADHD-related behaviors in 8-year-old children. Environ Health Perspect 123:888-894; http://dx.doi.org/10.1289/ehp.1408084.

No MeSH data available.


Related in: MedlinePlus

Conceptual representation of the pharmacokinetic model (Verner et al. 2013). Reproduced with permission from Environmental Health Perspectives.
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f1: Conceptual representation of the pharmacokinetic model (Verner et al. 2013). Reproduced with permission from Environmental Health Perspectives.

Mentions: Postnatal exposure assessment. We used PCB-153 as a proxy for total PCB exposure because of its long half-life in humans (Ritter et al. 2011) and its correlation with other prevalent PCB congeners in this population (Spearman correlation coefficients of 0.72 for PCB-118, 0.81 for PCB-138, and 0.73 for PCB-180). We estimated children’s serum lipid PCB-153 levels at each of the first 12 postnatal months using our previously published pharmacokinetic model (Verner et al. 2013). This model simulates lifetime exposure in the mother, transplacental diffusion during pregnancy, and transfer via breastfeeding after delivery (Figure 1). Both the mother and the child are represented in the model, and only body lipids are included because PCB-153 is highly lipophilic and binds almost exclusively to lipids. The model assumes a homogeneous distribution across body lipids, including serum lipids. Maternal exposure was parameterized as a constant daily dose (nanograms per kilogram body weight) calibrated to match measured cord serum PCB-153 levels at birth. Infants’ postnatal exposure through age 12 months was attributed entirely to breastfeeding.


Measured Prenatal and Estimated Postnatal Levels of Polychlorinated Biphenyls (PCBs) and ADHD-Related Behaviors in 8-Year-Old Children.

Verner MA, Hart JE, Sagiv SK, Bellinger DC, Altshul LM, Korrick SA - Environ. Health Perspect. (2015)

Conceptual representation of the pharmacokinetic model (Verner et al. 2013). Reproduced with permission from Environmental Health Perspectives.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4559949&req=5

f1: Conceptual representation of the pharmacokinetic model (Verner et al. 2013). Reproduced with permission from Environmental Health Perspectives.
Mentions: Postnatal exposure assessment. We used PCB-153 as a proxy for total PCB exposure because of its long half-life in humans (Ritter et al. 2011) and its correlation with other prevalent PCB congeners in this population (Spearman correlation coefficients of 0.72 for PCB-118, 0.81 for PCB-138, and 0.73 for PCB-180). We estimated children’s serum lipid PCB-153 levels at each of the first 12 postnatal months using our previously published pharmacokinetic model (Verner et al. 2013). This model simulates lifetime exposure in the mother, transplacental diffusion during pregnancy, and transfer via breastfeeding after delivery (Figure 1). Both the mother and the child are represented in the model, and only body lipids are included because PCB-153 is highly lipophilic and binds almost exclusively to lipids. The model assumes a homogeneous distribution across body lipids, including serum lipids. Maternal exposure was parameterized as a constant daily dose (nanograms per kilogram body weight) calibrated to match measured cord serum PCB-153 levels at birth. Infants’ postnatal exposure through age 12 months was attributed entirely to breastfeeding.

Bottom Line: We aimed to assess whether estimated serum PCB levels in infancy are associated with attention deficit/hyperactivity disorder (ADHD)-related behaviors at 8 years of age among children whose cord serum PCB levels were previously shown to be associated with ADHD-related behaviors.Cord serum PCB-153 levels (median, 38 ng/g lipids) were associated with ADHD-related behaviors, although statistical significance was observed with quantile regression models only at the 75th percentile.Measured prenatal and estimated postnatal levels of polychlorinated biphenyls (PCBs) and ADHD-related behaviors in 8-year-old children.

View Article: PubMed Central - PubMed

Affiliation: Channing Division of Network Medicine, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT

Background: Epidemiologic studies of postnatal PCB exposure and behavior have not reported consistent evidence of adverse associations, possibly because of challenges in exposure estimation. We previously developed a pharmacokinetic model to improve estimation of children's PCB exposure.

Objectives: We aimed to assess whether estimated serum PCB levels in infancy are associated with attention deficit/hyperactivity disorder (ADHD)-related behaviors at 8 years of age among children whose cord serum PCB levels were previously shown to be associated with ADHD-related behaviors.

Methods: We used a pharmacokinetic model to estimate monthly serum polychlorinated biphenyl (PCB)-153 levels in 441 infants (ages 1-12 months) based on parameters such as breastfeeding and cord serum PCB-153 levels. Behavior was evaluated at age 8 using the Conners' Rating Scale for Teachers (CRS-T). Associations between PCB-153 levels and ADHD-related CRS-T indices were assessed using multivariable quantile regression at the 50th and 75th percentiles of CRS-T scores, where higher percentiles reflect more adverse behaviors.

Results: Cord serum PCB-153 levels (median, 38 ng/g lipids) were associated with ADHD-related behaviors, although statistical significance was observed with quantile regression models only at the 75th percentile. Associations with postnatal exposure estimates were attenuated. For example, hyperactive-impulsive behavior scores at age 8 years were 0.9 points (95% CI: 0.2, 2.5), 0.5 points (95% CI: 0.3, 2.3), and 0.3 points (95% CI: -0.2, 1.5) higher in association with interquartile range increases in serum PCB-153 at birth, 2 months, and 12 months of age, respectively.

Conclusions: Associations between estimated postnatal PCB-153 exposures and ADHD-related behaviors at 8 years of age were weaker than associations with PCB-153 concentrations measured in cord serum at birth.

Citation: Verner MA, Hart JE, Sagiv SK, Bellinger DC, Altshul LM, Korrick SA. 2015. Measured prenatal and estimated postnatal levels of polychlorinated biphenyls (PCBs) and ADHD-related behaviors in 8-year-old children. Environ Health Perspect 123:888-894; http://dx.doi.org/10.1289/ehp.1408084.

No MeSH data available.


Related in: MedlinePlus