Burn pit exposure in military personnel: is there an effect on sleep-disordered breathing?

Purpose Exposure to elevated concentrations of respirable particulate matter (< 10 mu m) may influence sleep-disordered breathing. Burn pits as utilized by the US military in the Middle East until 2011 produced elevated particle matter concentrations. We seek to determine if subjective exposure to burn pits during deployment affects prevalence or severity of obstructive sleep apnea (OSA) in military personnel. Methods As part of a prospective observational study of previously deployed military personnel with exertional dyspnea (n = 145), all patients underwent pulmonary function testing, screening for burn pit exposure, and if warranted by questionnaires, overnight polysomnography. A total of 100 patients completed all testing. For analysis, patients were classified into a burn pit exposure group (45 patients) and a no exposure group (55 patients). Additional analyses were performed on those endorsing burn pit maintenance during deployment (25 patients) and those with > 12 h of daily exposure (17 patients). Results The prevalence of OSA, defined by apnea-hypopnea index (AHI) > 5/h, was similarly high in both groups (69% vs. 71%, p = 0.83). Surprisingly, the mean AHI was lower in the exposed group (12.8/h vs. 19.7/h, p = 0.04) while nadir of oxygen saturation was similar (87% vs. 86%, p = 0.39). Subgroup analyses revealed similar findings in those who performed burn pit maintenance (prevalence = 80%, p = 0.58; AHI = 14.8, p = 0.16) and those with > 12 h of daily exposure (prevalence = 88%, p = 0.33; AHI = 18.0, p = 0.62). Conclusions Subjective burn pit exposure does not appear to influence OSA development in previously deployed military personnel. Given the high rate of OSA in this cohort, continued investigation of deployment exposures which may influence sleep-disordered breathing is recommended.