Strong link between domestic violence and asthma

The link between environmental exposures and asthma has been clearly described, but a new study from researchers at the Harvard School of Public Health (HSPH) finds a strong association between domestic violence and asthma.

The study, in the upcoming June issue of the International Journal of Epidemiology, (published advance online Feb. 28, 2007) raises questions about the role of stress in the development of this common respiratory condition.

"Classic environmental triggers for asthma have been carefully studied, but there is less information on the role of stress in asthma episodes," says lead researcher S.V. Subramanian, Assistant Professor in the Department of Society, Human Development and Health at HSPH. "The risk posed by domestic violence - and perhaps other psychosocial factors - could be as high as some well known environmental risk factors such as smoking."

The authors performed their research using a large nationally representative database of 92,000 households in India, where domestic violence is highly prevalent. Each respondent was surveyed in a face-to-face interview in one of 18 Indian languages. Respondents were asked if anyone in the household suffered from asthma, and were also asked about a personal history of experiencing or witnessing domestic violence. Researchers also accounted for many other factors that have been associated with asthma, including exposure to tobacco smoke and level of education and income.

The study found that women who had experienced domestic violence in the past year had a 37 percent increased risk of asthma. For women who had not experienced domestic violence themselves but lived in a household where a woman had been beaten in the past year, there was a 21 percent increased risk of asthma than for women who did not live in such households. In addition, living in a household where a woman experienced domestic violence also increased the risk of reported asthma in children and adult men.

While the authors caution that the study cannot prove a causal link between domestic violence and asthma, there are several possible mechanisms to explain such a strong relationship between the two. Exposure to violence, and other major psychosocial stressors, is known to affect the immune system and inflammation, which have a role in asthma development. In addition, those exposed to violence may adopt certain "Coping" behaviors that predispose them to asthma, such as cigarette smoking.

This study is the first to examine the relationship between violence and asthma in India, where domestic violence is at relatively high levels, and where the World Health Organization estimates 15-20 million asthmatics live. Subramanian adds, "Our study suggests a new method for identifying stress-induced episodes and also reveals another terrible health risk of domestic violence."