Parental stress increases children’s risk for asthma from pollution
MedWire News: Children with highly stressed parents are more susceptible to the development of asthma associated with environmental triggers such as traffic pollution and tobacco smoke than children with less stressed parents, research suggests.
“Air pollution can promote inflammatory responses in the airways of the lung, which is a central feature of asthma,” explained lead researcher Rob McConnell, from the University of Southern California in Los Angeles, USA. “Stress may also have pro-inflammatory effects and this may help explain why the two exposures together were important.”
McConnell and team studied data on 2497 children without a previous history of asthma or wheeze who participated in the Children’s Health Study, a longitudinal study of respiratory health among children in 13 southern California communities.
The children, who were aged between 5 and 9 years at baseline in 2002-2003, were followed up for 3 years and any new cases of doctor-diagnosed asthma were recorded.
Data on parental stress, parental education – an indicator of socioeconomic status – and exposure to tobacco smoke in utero were collected at baseline. Exposure to traffic-related pollution was estimated by analyzing the proximity of participant’s homes to busy roads.
Over the course of the 3-year study, 120 of the children developed asthma.
The researchers found that parental stress alone was not associated with an increased risk for asthma in children.
However, among children exposed to high pollution levels, those with highly stressed parents were around 1.5 times more likely to develop asthma during follow-up than children of parents with low stress levels.
Furthermore, high levels of parental stress were also associated with an increased risk for asthma among children exposed to tobacco smoke in utero.
The researchers also note that low socioeconomic status increased the risk for asthma associated with exposure to traffic pollution and tobacco smoke in utero.
“These results suggest that children from stressful households are more susceptible to the effects of traffic-related pollution and in utero tobacco smoke on the development of asthma,” the researchers conclude in the Proceedings of the National Academy of Sciences.
McConnell added: “Childhood asthma is a complex disease that probably has many contributing causes.
“Further study of effects of exposure to air pollution in combination with stressful environments associated with poverty and other social factors could contribute to our understanding of why the disease develops.”
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By Mark Cowen