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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

Examples of measured cord serum lipid and estimated postnatal serum lipid PCB-153 levels over the first 12 months of life in four study infants with different durations of breastfeeding and cord serum levels: (A) 2 months of breastfeeding, 91 ng PCB-153/g lipids in cord serum; (B) no breastfeeding, 64 ng PCB-153/g lipids in cord serum; (C) 5 months of breastfeeding, 93 ng PCB-153/g lipids in cord serum; (D) 10 months of breastfeeding, 54 ng PCB-153/g lipids in cord serum. The vertical dotted lines represent the age at which breastfeeding stopped for the three infants who were breastfed.
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f2: Examples of measured cord serum lipid and estimated postnatal serum lipid PCB-153 levels over the first 12 months of life in four study infants with different durations of breastfeeding and cord serum levels: (A) 2 months of breastfeeding, 91 ng PCB-153/g lipids in cord serum; (B) no breastfeeding, 64 ng PCB-153/g lipids in cord serum; (C) 5 months of breastfeeding, 93 ng PCB-153/g lipids in cord serum; (D) 10 months of breastfeeding, 54 ng PCB-153/g lipids in cord serum. The vertical dotted lines represent the age at which breastfeeding stopped for the three infants who were breastfed.

Mentions: We simulated PCB-153 levels in infants using a pharmacokinetic model that assumes that all postnatal exposure during the first year of life is from breastfeeding. Four representative plots of PCB-153 levels are shown for infants with different durations of breastfeeding in Figure 2. Estimated infants’ serum PCB-153 increased during lactation, peaked at the end of breastfeeding, and subsequently decreased with cessation of postnatal exposure and dilution of body burden with growth and expanding body lipids. Among breastfed infants, the increase in estimated serum PCB-153 levels over time was steeper in infants whose measured cord serum level at birth was higher (Figure 2A and C compared with D). Levels of serum PCB-153 that were accumulated prenatally declined rapidly after delivery in infants who were not exposed via breastfeeding (Figure 2B). Because of the relatively low prevalence of breastfeeding in this population, median estimated serum PCB-153 levels declined from 38 ng/g lipids at birth to 30 ng/g lipids at 2 months and 14 ng/g lipids at 12 months (see Supplemental Material, Figure S1) despite the fact that levels increased in breastfed infants. Estimated PCB-153 levels in infants’ serum were highly correlated with measured cord serum levels. The Spearman correlation coefficients between cord serum PCB-153 levels and postnatal estimates decreased from the first month (r = 0.93) to the 6th month (r = 0.70) and stabilized around 0.67 thereafter. On the other hand, the Spearman correlation between the total duration of breastfeeding and serum PCB-153 levels increased from 0.06 at birth to 0.68 at 6 months of age and stabilized around 0.70 thereafter (see Supplemental Material, Figure S2). This increasing correlation was expected because the duration of breastfeeding is the most influential model parameter during the first year (Verner et al. 2013).


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)

Examples of measured cord serum lipid and estimated postnatal serum lipid PCB-153 levels over the first 12 months of life in four study infants with different durations of breastfeeding and cord serum levels: (A) 2 months of breastfeeding, 91 ng PCB-153/g lipids in cord serum; (B) no breastfeeding, 64 ng PCB-153/g lipids in cord serum; (C) 5 months of breastfeeding, 93 ng PCB-153/g lipids in cord serum; (D) 10 months of breastfeeding, 54 ng PCB-153/g lipids in cord serum. The vertical dotted lines represent the age at which breastfeeding stopped for the three infants who were breastfed.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f2: Examples of measured cord serum lipid and estimated postnatal serum lipid PCB-153 levels over the first 12 months of life in four study infants with different durations of breastfeeding and cord serum levels: (A) 2 months of breastfeeding, 91 ng PCB-153/g lipids in cord serum; (B) no breastfeeding, 64 ng PCB-153/g lipids in cord serum; (C) 5 months of breastfeeding, 93 ng PCB-153/g lipids in cord serum; (D) 10 months of breastfeeding, 54 ng PCB-153/g lipids in cord serum. The vertical dotted lines represent the age at which breastfeeding stopped for the three infants who were breastfed.
Mentions: We simulated PCB-153 levels in infants using a pharmacokinetic model that assumes that all postnatal exposure during the first year of life is from breastfeeding. Four representative plots of PCB-153 levels are shown for infants with different durations of breastfeeding in Figure 2. Estimated infants’ serum PCB-153 increased during lactation, peaked at the end of breastfeeding, and subsequently decreased with cessation of postnatal exposure and dilution of body burden with growth and expanding body lipids. Among breastfed infants, the increase in estimated serum PCB-153 levels over time was steeper in infants whose measured cord serum level at birth was higher (Figure 2A and C compared with D). Levels of serum PCB-153 that were accumulated prenatally declined rapidly after delivery in infants who were not exposed via breastfeeding (Figure 2B). Because of the relatively low prevalence of breastfeeding in this population, median estimated serum PCB-153 levels declined from 38 ng/g lipids at birth to 30 ng/g lipids at 2 months and 14 ng/g lipids at 12 months (see Supplemental Material, Figure S1) despite the fact that levels increased in breastfed infants. Estimated PCB-153 levels in infants’ serum were highly correlated with measured cord serum levels. The Spearman correlation coefficients between cord serum PCB-153 levels and postnatal estimates decreased from the first month (r = 0.93) to the 6th month (r = 0.70) and stabilized around 0.67 thereafter. On the other hand, the Spearman correlation between the total duration of breastfeeding and serum PCB-153 levels increased from 0.06 at birth to 0.68 at 6 months of age and stabilized around 0.70 thereafter (see Supplemental Material, Figure S2). This increasing correlation was expected because the duration of breastfeeding is the most influential model parameter during the first year (Verner et al. 2013).

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