TY - JOUR
T1 - Breastfeeding as a modifier of the respiratory effects of air pollution in children
AU - Dong, Guang Hui
AU - Qian, Zhengmin
AU - Liu, Miao Miao
AU - Wang, Da
AU - Ren, Wan Hui
AU - Bawa, Shahida
AU - Fu, John
AU - Wang, Jing
AU - Lewis, Roger
AU - Zelicoff, Alan
AU - Simckes, Maayan
AU - Trevathan, Edwin
PY - 2013/5
Y1 - 2013/5
N2 - BACKGROUND: Breastfeeding and air pollution are both important factors for respiratory symptoms and asthma in children. Few studies have examined possible interaction between them on respiratory outcomes. METHODS: We studied 31,049 Chinese children, ages 2-14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2008-2009. Parents or guardians completed questionnaires about the children's histories of respiratory conditions, risk factors, and feeding methods. Three-year average concentrations of particles with an aerodynamic diameter ≤10 μm, sulfur dioxide, nitrogen dioxides, and ozone were calculated from monitoring stations in 25 study districts. We used two-level logistic regressions to examine the effects of exposure, controlling for covariates. RESULTS: Association of air pollution with childhood respiratory conditions was modified by breastfeeding. Compared with children who had been breastfed, those who were not exhibited consistently stronger effects of air pollution. Among non-breastfed children, odds ratios (ORs) per 10 μg/m increase in nitrogen dioxide were 1.40 (95% confidence interval = 1.19-1.64) for cough, 1.41 (1.16-1.71) for phlegm, 1.17 (1.00-1.36) for current wheeze, and 1.25 (1.07-1.46) for doctor-diagnosed asthma. For breastfed children, the ORs were 1.25 (1.09-1.43) for cough, 1.15 (0.99-1.34) for phlegm, 0.97 (0.87-1.08) for current wheeze, and 1.17 (1.05-1.32) for doctor-diagnosed asthma. Breastfeeding was more protective among younger children. Breastfeeding was also associated with reduced effects of passive smoke exposure in children. CONCLUSION: Breastfeeding is associated with smaller associations between air pollution and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of pollutants.
AB - BACKGROUND: Breastfeeding and air pollution are both important factors for respiratory symptoms and asthma in children. Few studies have examined possible interaction between them on respiratory outcomes. METHODS: We studied 31,049 Chinese children, ages 2-14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2008-2009. Parents or guardians completed questionnaires about the children's histories of respiratory conditions, risk factors, and feeding methods. Three-year average concentrations of particles with an aerodynamic diameter ≤10 μm, sulfur dioxide, nitrogen dioxides, and ozone were calculated from monitoring stations in 25 study districts. We used two-level logistic regressions to examine the effects of exposure, controlling for covariates. RESULTS: Association of air pollution with childhood respiratory conditions was modified by breastfeeding. Compared with children who had been breastfed, those who were not exhibited consistently stronger effects of air pollution. Among non-breastfed children, odds ratios (ORs) per 10 μg/m increase in nitrogen dioxide were 1.40 (95% confidence interval = 1.19-1.64) for cough, 1.41 (1.16-1.71) for phlegm, 1.17 (1.00-1.36) for current wheeze, and 1.25 (1.07-1.46) for doctor-diagnosed asthma. For breastfed children, the ORs were 1.25 (1.09-1.43) for cough, 1.15 (0.99-1.34) for phlegm, 0.97 (0.87-1.08) for current wheeze, and 1.17 (1.05-1.32) for doctor-diagnosed asthma. Breastfeeding was more protective among younger children. Breastfeeding was also associated with reduced effects of passive smoke exposure in children. CONCLUSION: Breastfeeding is associated with smaller associations between air pollution and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of pollutants.
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U2 - 10.1097/EDE.0b013e3182877eb8
DO - 10.1097/EDE.0b013e3182877eb8
M3 - Article
C2 - 23429406
AN - SCOPUS:84876283559
VL - 24
SP - 387
EP - 394
JO - Epidemiology
JF - Epidemiology
SN - 1044-3983
IS - 3
ER -