TPS 741: Adverse birth outcomes 2, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM
Background: There is evidence that exposures to polycyclic aromatic hydrocarbon (PAH) in air pollution and to fine particulate air pollution are associated with higher childhood body mass index (BMI) and obesity risk.
Methods: African-American and Hispanic children born in the Bronx or Northern Manhattan, New York (1998-2006), whose mothers underwent personal air monitoring for airborne PAH exposure during pregnancy, were followed up with height and weight measurements at approximate ages 5, 7, 9, 10, 11, 12.5 and 13.5 years. Multivariable generalized estimating equation analyses were used to relate pre-natal airborne PAH exposures to child BMI Z-scores through time. The analyses adjusted for many known risk factors for childhood obesity. Interaction terms between tertile categories of prenatal PAH exposure and age and age squared were included in the model.
Results: In total, 535 children had at least one height and weight measure during follow-up. The prevalence of obesity was 20.6% at age 5 and increased across follow-ups until age 11 when it was 33.0%. At age 5, BMI Z-scores were significantly greater for children in the third tertile of exposure relative to the first tertile (0.35 Z-score units, 95% CI 0.09, 0.61, p=0.007) and were non-significantly higher for the second tertile of exposure compared to the first tertile (0.25 Z-score units, 95% CI -0.02, 0.52, P=0.075). The trajectories of BMI Z-scores by tertiles of exposure converged as the children aged, such that by age 11 years the estimated mean BMI Z-scores associated with each tertile of exposure were not different.
Conclusions: Prenatal exposures to airborne PAH were associated with higher childhood BMI Z-scores at a young age, but growth trajectories converged by age 11 years. Accordingly, highly exposed children spend a greater proportion of their childhood with higher BMI Z-scores, the health significance of this finding will need to be examined.