Hsu HL, Chiu YM, Coull BA, Kloog I, Schwartz J, Lee A, Wright RO, Wright RJ. Prenatal Particulate Air Pollution and Asthma Onset in Urban Children: Identifying Sensitive Windows and Sex Differences. Am J Respir Crit Care Med. 2015 Jul 15. [Epub ahead of print]
Am J Respir Crit Care Med. 2015 Jul 15. [Epub ahead of print]
Prenatal Particulate Air Pollution and Asthma Onset in Urban Children: Identifying Sensitive Windows and Sex Differences.
Hsu HL(1), Chiu YM(2), Coull BA(3), Kloog I(4), Schwartz J(5), Lee A(6), Wright RO(7), Wright RJ(8,)(9).
RATIONALE: The influence of particulate air pollution on respiratory health starts in utero. Fetal lung growth and structural development occurs in stages, thus effects on postnatal respiratory disorders may differ based on timing of exposure.
OBJECTIVES: We implemented an innovative method to identify sensitive windows for effects of prenatal exposure to particulate matter with a diameter≤2.5μm (PM2.5) on children's asthma development in an urban pregnancy cohort.
METHODS & MEASURES: Analyses included 736 full-term (≥37 weeks) children. Each mother's daily PM2.5 exposure was estimated over gestation using a validated satellite-based spatio-temporal resolved model. Using distributed lag models (DLMs), we examined associations between weekly averaged PM2.5 levels over pregnancy and physician diagnosed asthma in children by age 6 years. Effect modification by sex was also examined.
MAIN RESULTS: Most mothers were ethnic minorities (54% Hispanic, 30% black), had ≤12 years of education (66%) and did not smoke in pregnancy (80%). In the sample as a whole, DLMs adjusting for child age, sex, and maternal factors (education, race/ethnicity, smoking, stress, atopy, pre-pregnancy obesity) showed that increased PM2.5 exposure levels at 16-25 weeks gestation were significantly associated with early childhood asthma development. An interaction between PM2.5 and sex was significant (p=0.01) with sex-stratified analyses showing that the association exists only for boys.
CONCLUSIONS: Higher prenatal PM2.5 exposure at mid-gestation was associated with asthma development by age 6 years in boys. Methods to better characterize vulnerable windows may provide insight into underlying mechanisms.
PMID: 26176842 [PubMed - as supplied by publisher]