Comorbid insomnia and sleep apnea in Veterans with post-traumatic stress disorder

The purpose of this study was to determine the impact of insomnia in Veterans with post-traumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) on health-related outcomes before and after 12 weeks of continuous positive airway pressure (CPAP) treatment. We conducted a prospective cohort study of Veterans with PTSD and documented apnea hypopnea index (AHI) 5 with and without clinically significant insomnia as determined by the Insomnia Severity Index (ISI). Health-related outcomes including PTSD checklist (PCL-M), SF-36, and Pittsburgh Sleep Quality Index (PSQI) were assessed at baseline and 12 weeks after initiation of OSA treatment. CPAP adherence was retrieved at each visit. Seventy-two Veterans including 36 with comorbid insomnia and OSA (COMISA) and 36 OSA-only were enrolled. Veterans with COMISA were younger (p = 0.03), had lower BMI (p < 0.001), and were more likely to report depression than those with OSA-only (p = 0.004). Although AHI was higher in the COMISA (p = 0.01), both groups expressed comparable daytime sleepiness (p = 0.16). The COMISA group had no significant change in SF-36 and PSQI after 12 weeks of treatment and used CPAP much less frequently than OSA-only group (p = 0.001). COMISA in Veterans with PTSD is associated with worse quality of life than those with OSA-only. Insomnia should be assessed in Veterans with PTSD who are not adherent to CPAP treatment.