Correlations of sleep disorders with severity of obstructive airway disease in mustard gas-injured patients

Abstract

Mustard gas has serious adverse effects on several organs and functions in humans. In this study, we analyzed potential correlations between obstructive airway disease and sleep disorders in Iranian mustard gas-injured patients. We enrolled 30 male mustard gas-injured veterans and civilians from the Chemical Warfare Exposure Clinic at Baqiyatallah Hospital, Tehran. All the subjects underwent comprehensive polysomnographic and spirometric evaluations for diagnosis of sleep disorders. Patients were categorized into three groups according to the severity of their obstructive airway disease based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria: group 1 (GOLD I and II), group 2 (GOLD III), and group 3 (GOLD IV). Patients with less severe obstructive airway disease had significantly higher rate of hypopnea (p = 0.05) and AHI (p = 0.05). The number of REM events was significantly higher in patients with less severe airway disease (p = 0.028). Stage 1 sleep among patients with higher FEV1 significantly constituted a higher proportion of sleep, and stage 4 sleep was significantly longer in patients with higher DLCO (p = 0.043, both). We found that sleep parameters in SM-exposed patients have some relations with spirometric parameters. Future studies with large patient populations are needed for confirmation of our results, and therapeutic interventions are needed to evaluate endeavors we can do to enhance health and quality of life in our mustard gas-injured population.