Sarcoidosis risk among U.S. Veterans exposed to inorganic dust during military service

RATIONALE: Sarcoidosis disproportionately affects U.S. military Veterans. Its rising incidence and prevalence among Veterans are higher than in civilians and vary by branch of service, suggesting a role for prior military exposures. OBJECTIVES: To investigate whether estimated service-related exposure to inorganic dust is associated with increased risk of sarcoidosis. METHODS: In a retrospective nested case-control study of Veterans enrolled in the Veterans Health Administration (VHA) who received VHA- or Medicare-covered care, sarcoidosis cases identified in electronic health records between 2002 and 2022 were each matched to five controls by propensity scores and incidence density sampling by calendar year. To estimate inorganic dust exposure, military occupational codes (MOCs) were linked to a job exposure matrix (JEM). Multivariable conditional logistic regression analyses were adjusted for demographics, geography, rurality, and service branch. The attributable fraction among the exposed was calculated. In secondary analyses, latency from service separation to diagnosis was assessed. In sensitivity analyses, exposure misclassification was assessed by using a modified JEM weighted for MOC coding precision and by examining only post-9/11 Veterans; service duration was also analyzed. RESULTS: Among >16 million individuals evaluated, 3,019,636 Veterans had at least one MOC; 5,855 incident cases and 29,275 controls were analyzed. Inorganic dust exposure was associated with increased risk of sarcoidosis (conditional odds ratio [cOR]: 1.08; 95% confidence interval [CI], 1.003-1.170); the attributable fraction was 7.6%. Associations were stronger with a modified JEM score (cOR: 1.15; 95% CI 1.05-1.27) and when restricted to post-9/11 Veterans (cOR: 1.25; 95% CI 1.07-1.47). In latency analysis, sarcoidosis risk peaked 2-5 years post-service (cOR: 2.10; 95% CI: 1.20-3.58). CONCLUSION: Occupational and environmental exposure to inorganic dust during military service was associated with increased risk of sarcoidosis among Veterans, carrying potential implications for prevention and surveillance.