Study Links PTSD to Higher Risk of Asthma in 911 WorkersAug 31, 2016
Findings published in the American Journal of Respiratory and Critical Care Medicine suggest that 9/11 workers with post-traumatic stress disorder are more likely to develop new-onset asthma. Researchers at the Children’s Hospital of Pittsburgh conducted a longitudinal study with a follow-up of 5 years. PTSD in 9/11 workers was associated with a more than two-fold increased risk of asthma.
The researchers wrote, “This finding strongly supports an expanding body of literature linking stress-related disorders such as PTSD to the pathogenesis of asthma, and suggests that physicians treating adults with PTSD should be aware of their potentially increased risk of asthma,".
Probable PTSD was associated with clinically significant bronchodilator response (BDR) among non-firefighter 9/11 workers in the study at baseline. Bronchodilators are a class of medications given to patients with asthma and chronic obstructive pulmonary disease (COPD). They are used to help open up the airways. If a patient has clinically significant BDR, it is a sign of respiratory problems. The study suggests that PTSD may be an independent risk factor for asthma.
The study involved 3,757 9/11 workers who have never smoked and did not have asthma at the beginning of the study. After five years, researchers found that those with PTSD had a 2.41-fold increased risk of new-onset asthma after adjustment for other factors such as age and gender. Participants with BDR at baseline had a 3.13-fold increased risk of asthma.
"We looked at lifetime non-smokers to avoid the risk that asthma may be confused with COPD," said study author Juan Celedón, MD to Medpage Today.
PTSD has been linked to asthma in 9/11 workers in prior studies, but this is the first to look at people who did not have asthma at the start of the study. By eliminating people who have asthma at baseline, researchers reduce the likelihood that asthma was caused by outside factors. Additionally, it means that PTSD is not likely to have been caused by asthma.
The study authors wrote, "Unlike results from previous cross-sectional studies, 'reverse causation' (e.g., asthma leading to PTSD symptoms) is an improbable explanation for our findings for incident asthma, since this analysis was first conducted after excluding subjects who had a pre-existing asthma diagnosis at baseline, and then repeated after further exclusion of subjects with clinically significant BDR at baseline, obtaining very similar results,".
The study had its limitations, including confounding factors of PTSD and asthma, such as other mental illness, family history of asthma, or exposure to environmental hazards other than 9/11 and smoking. Furthermore, the study did not have BDR data for the first visit or information about a clinical diagnosis of PTSD.