Abstract Rationale Veterans previously deployed to the Southwest Asia Theater of Military Operations have a higher incidence of new-onset asthma and greater utilization of asthma-related healthcare compared to non-deployers. Although deployment- related inhalational exposures are suspected contributors, these exposures are highly heterogeneous, and whether specific exposure profiles uniquely associate with asthma remains unclear. Recent studies have identified that specific Military Vapors, Gases, Dusts, Fumes (VGDF) occupational exposures are associated with increased respiratory symptoms, in addition to variable associations with burn pit smoke exposures. Therefore, we assessed deployment exposures in a well-characterized cohort of Veterans undergoing clinical evaluation for respiratory symptoms within the Veterans Affairs (VA)’s Post-Deployment Cardiopulmonary Evaluation Network (PDCEN) to better understand relationships between these exposures, asthma and abnormal lung function. Methods 214 symptomatic Veterans were evaluated and classified into the following groups based on pulmonary function and bronchoprovocation testing: 1) asthma (definite, probable, possible), 2) restrictive and/or obstructive impairment, or 3) normal pulmonary function. All Veterans completed a standardized exposure questionnaire (VA CSP#595 SHADE) that assessed five exposures domains: Burn Pit, Ground Dust/Engine Exhaust, Other Combustion Byproducts, Toxicants, and Military-Related VGDF. Differences in exposure domain scores among groups were examined using linear models adjusted for age and sex, with multiple testing correction using the Benjamini-Hochberg method. A heatmap was constructed to visualize the distribution and relative composition of VGDF exposures across asthma classification groups. Results Of the 214 Veterans, 91 had asthma (24.3% definite, 8.9% probable, 9.3% possible), 42(19.6%) had restriction and/or fixed obstruction, and 81(37.9%) had normal pulmonary function. Although the military VGDF score did not differ significantly among groups, a decreasing gradient emerged from definite asthma with the highest value (25.7±23.4) to normal pulmonary function with the lowest value (16.6±17.0). Additionally, burn pit exposure scores differed significantly among groups (P = 0.046; corrected P = 0.12). Figure illustrates the complexity of military VGDF exposure among veterans and identifies refueling as a frequently reported exposure, particularly within asthma groups. Conclusion Characterizing the effects of occupational exposures on airway disease has critical implications for millions of veterans. We observed a decreasing gradient in military VGDF scores corresponding to asthma probability, with the definite asthma group exhibiting the highest VGDF score and most complex exposure compositions. These findings underscore the importance of characterizing deployment-related exposures in understanding asthma pathophysiology and guiding targeted preventative and clinical strategies for affected Veterans. Additional study assessing the role of mixed exposures may clarify exposure-health relationships further. This abstract is funded by: the VA’s Airborne Hazards and Burn Pits Center of Excellence Contract No 36C24223D0086
Huang et al. (Fri,) studied this question.