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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

Quantile regression effect estimates for the 50th (top) and 75th percentiles (bottom) of scores for the Conners’ Rating Scale for Teachers (CRS-T) ADHD-related indices (n = 441). Circles represent the change in CRS-T score at age 8 years for an IQR increase in serum lipid PCB-153 levels measured in cord serum at birth and estimated for each month of infancy [time (months) and IQRs (ng/g lipids): 0 (birth) = 42; 1 = 49; 2 = 49; 3 = 44; 4 = 44; 5 = 45; 6 = 42; 7 = 42; 8 = 40; 9 = 39; 10 = 37; 11 = 36; 12 = 34]. Error bars represent the 95% CIs. Models were adjusted for maternal prepregnancy weight, gestational weight gain, characteristics at delivery (age, marital status, education, parity), seafood consumption during pregnancy, use of tobacco and alcohol during pregnancy and use of illicit drugs in the year before delivery, and IQ at 8-year follow-up; total household income (at delivery) and HOME score at 8-year assessment; and child sex, race, cord blood lead level, ADHD medication use, school type, and age at CRS-T evaluation.
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f3: Quantile regression effect estimates for the 50th (top) and 75th percentiles (bottom) of scores for the Conners’ Rating Scale for Teachers (CRS-T) ADHD-related indices (n = 441). Circles represent the change in CRS-T score at age 8 years for an IQR increase in serum lipid PCB-153 levels measured in cord serum at birth and estimated for each month of infancy [time (months) and IQRs (ng/g lipids): 0 (birth) = 42; 1 = 49; 2 = 49; 3 = 44; 4 = 44; 5 = 45; 6 = 42; 7 = 42; 8 = 40; 9 = 39; 10 = 37; 11 = 36; 12 = 34]. Error bars represent the 95% CIs. Models were adjusted for maternal prepregnancy weight, gestational weight gain, characteristics at delivery (age, marital status, education, parity), seafood consumption during pregnancy, use of tobacco and alcohol during pregnancy and use of illicit drugs in the year before delivery, and IQ at 8-year follow-up; total household income (at delivery) and HOME score at 8-year assessment; and child sex, race, cord blood lead level, ADHD medication use, school type, and age at CRS-T evaluation.

Mentions: In line with a previous study of the same cohort where children in the highest quartile of cord serum PCB levels had increased risks of ADHD-related behavior in a log risk regression analysis (Sagiv et al. 2010), results from the current quantile regression analyses also suggest that cord serum PCB-153 levels are associated with greater ADHD-related behavior as reflected in three of the four CRS-T subscales assessed (DSM-IV Total index, DSM-IV Hyperactive-Impulsive index, and Conners’ ADHD index). However, these associations were statistically significant in quantile regression models only at the 75th percentile (Figure 3). The association between PCB-153 and ADHD-related behaviors at age 8 years was stronger with measured cord serum levels than with estimated postnatal serum levels; the strength and significance of the associations attenuated substantially over time within the first few months of estimated postnatal exposure (Figure 3). The most sustained association with postnatal exposure estimates was a modest statistically significant association of estimated serum PCB-153 levels through age 6 months with greater DSM-IV Hyperactive-Impulsive index and Conners’ ADHD index behaviors at age 8 years (quantile regression models at the 75th percentile), but these associations also attenuated over time (Figure 3). For example, the increase in Hyperactive-Impulsive index behaviors at age 8 years associated with an IQR increase in PCB-153 levels was 0.9 point at birth [95% confidence interval (CI): 0.2, 2.5], 0.5 point at 2 months (95% CI: 0.3, 2.3), and 0.3 point at 12 months (95% CI: –0.2, 1.5). Because quantile regression does not assume any particular distribution of residuals, it is possible for CIs to be asymmetrical, which is the case in most of our regression models.


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)

Quantile regression effect estimates for the 50th (top) and 75th percentiles (bottom) of scores for the Conners’ Rating Scale for Teachers (CRS-T) ADHD-related indices (n = 441). Circles represent the change in CRS-T score at age 8 years for an IQR increase in serum lipid PCB-153 levels measured in cord serum at birth and estimated for each month of infancy [time (months) and IQRs (ng/g lipids): 0 (birth) = 42; 1 = 49; 2 = 49; 3 = 44; 4 = 44; 5 = 45; 6 = 42; 7 = 42; 8 = 40; 9 = 39; 10 = 37; 11 = 36; 12 = 34]. Error bars represent the 95% CIs. Models were adjusted for maternal prepregnancy weight, gestational weight gain, characteristics at delivery (age, marital status, education, parity), seafood consumption during pregnancy, use of tobacco and alcohol during pregnancy and use of illicit drugs in the year before delivery, and IQ at 8-year follow-up; total household income (at delivery) and HOME score at 8-year assessment; and child sex, race, cord blood lead level, ADHD medication use, school type, and age at CRS-T evaluation.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f3: Quantile regression effect estimates for the 50th (top) and 75th percentiles (bottom) of scores for the Conners’ Rating Scale for Teachers (CRS-T) ADHD-related indices (n = 441). Circles represent the change in CRS-T score at age 8 years for an IQR increase in serum lipid PCB-153 levels measured in cord serum at birth and estimated for each month of infancy [time (months) and IQRs (ng/g lipids): 0 (birth) = 42; 1 = 49; 2 = 49; 3 = 44; 4 = 44; 5 = 45; 6 = 42; 7 = 42; 8 = 40; 9 = 39; 10 = 37; 11 = 36; 12 = 34]. Error bars represent the 95% CIs. Models were adjusted for maternal prepregnancy weight, gestational weight gain, characteristics at delivery (age, marital status, education, parity), seafood consumption during pregnancy, use of tobacco and alcohol during pregnancy and use of illicit drugs in the year before delivery, and IQ at 8-year follow-up; total household income (at delivery) and HOME score at 8-year assessment; and child sex, race, cord blood lead level, ADHD medication use, school type, and age at CRS-T evaluation.
Mentions: In line with a previous study of the same cohort where children in the highest quartile of cord serum PCB levels had increased risks of ADHD-related behavior in a log risk regression analysis (Sagiv et al. 2010), results from the current quantile regression analyses also suggest that cord serum PCB-153 levels are associated with greater ADHD-related behavior as reflected in three of the four CRS-T subscales assessed (DSM-IV Total index, DSM-IV Hyperactive-Impulsive index, and Conners’ ADHD index). However, these associations were statistically significant in quantile regression models only at the 75th percentile (Figure 3). The association between PCB-153 and ADHD-related behaviors at age 8 years was stronger with measured cord serum levels than with estimated postnatal serum levels; the strength and significance of the associations attenuated substantially over time within the first few months of estimated postnatal exposure (Figure 3). The most sustained association with postnatal exposure estimates was a modest statistically significant association of estimated serum PCB-153 levels through age 6 months with greater DSM-IV Hyperactive-Impulsive index and Conners’ ADHD index behaviors at age 8 years (quantile regression models at the 75th percentile), but these associations also attenuated over time (Figure 3). For example, the increase in Hyperactive-Impulsive index behaviors at age 8 years associated with an IQR increase in PCB-153 levels was 0.9 point at birth [95% confidence interval (CI): 0.2, 2.5], 0.5 point at 2 months (95% CI: 0.3, 2.3), and 0.3 point at 12 months (95% CI: –0.2, 1.5). Because quantile regression does not assume any particular distribution of residuals, it is possible for CIs to be asymmetrical, which is the case in most of our regression models.

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