LAUSR

BACKGROUND Post-traumatic stress disorder (PTSD) has been linked to respiratory symptoms and functional limitations, but the mechanism(s) leading to this association are poorly defined. RESEARCH QUESTION What is the relationship between PTSD, lung function, and the cardiopulmonary response to exercise in combat veterans presenting with chronic respiratory symptoms? STUDY DESIGN and Methods: We prospectively enrolled military service members with respiratory symptoms following deployment to southwest Asia (SWA). All participants underwent a comprehensive evaluation to include pulmonary function (PFT) and cardiopulmonary exercise (CPET) testing. We compared PFT variables and cardiopulmonary response to exercise in subjects with and without PTSD using multivariable linear regression to adjust for confounders. RESULTS 303 participants were included (PTSD =70; Non-PTSD =233). Those with PTSD had a greater frequency of current respiratory complaints. There were no differences in measures for airway disease or lung volumes, but patients with PTSD had a reduction in diffusing capacity (DLCO) that was eliminated after adjustment for differences in hemoglobin levels. Participants with PTSD had a lower anaerobic threshold (AT) (23.9 vs 26.4 cc/kg/min; p =0.004), peak oxygen pulse (19.7 vs 18.5 cc/beat; p=0.03) and peak oxygen uptake (peakVO2) (34.5 cc/kg/min vs 38.8 cc/kg/min, p <0.001). No significant difference was observed in gas-exchange, respiratory reserve, or effort at peak exercise between participants with and without PTSD.