Mediating role of expressive suppression between psychological stress and sleep disturbances in military personnel stationed at extremely high altitudes: A cross-sectional study based on structural equation modeling

Abstract Objective To explore the group characteristics of emotion regulation strategies and their mediating mechanism between psychological stress and sleep disorders among military personnel stationed at altitudes. Methods A cross-sectional study was conducted on 401 servicemen subjected with convenience sampling from a troop stationed at Garze Tibetan Autonomous Prefecture, Sichuan Province (3 980 to 4 200 m) during December 2024 and April 2025. Psychological stress self-evaluation test for military personnel (PSET), emotion regulation questionnaire (ERQ), and Pittsburgh sleep quality index (PSQI) were used for evaluation. Structural equation modeling was employed to analyze the mediating effects of emotion regulation strategies between psychological stress and sleep disorders. Results The incidence of sleep disorders was 20.2% among ultra-high-altitude military personnel, and the incidence of mild sleep disorder 18.45%. Sleep disorder total score showed significant positive correlations with expressive suppression and psychological stress (r=0.23, 0.53, P