1026 Daytime Symptom Burden and Psychological Distress in Greek Patients with Obstructive Sleep Apnea and COMISA: Findings from a Clinical Cohort

Abstract Introduction Comorbid insomnia and obstructive sleep apnea (COMISA) represent a common yet frequently under-recognized clinical phenotype, characterized by a heightened symptom burden and impaired quality of life compared with obstructive sleep apnea (OSA) alone. Growing evidence indicates that the coexistence of insomnia symptoms may exacerbate daytime dysfunction, psychological distress, and treatment non-adherence. However, data from Mediterranean populations remain limited. This study aimed to evaluate key daytime symptoms—sleepiness and fatigue—and the psychological profile of patients with COMISA in a Greek clinical population, factors known to influence prognosis and therapeutic engagement. Methods Data were collected from three Sleep Medicine Clinics of University hospitals. Participants underwent either laboratory polysomnography or home sleep testing and completed validated questionnaires: the Epworth Sleepiness Scale (ESS) for daytime sleepiness, Fatigue Severity Scale (FSS) for fatigue, Athens Insomnia Scale (AIS) for insomnia symptoms, and the Hospital Anxiety and Depression Scale (HADS-A/HADS-D) for psychological distress. OSA was defined as apnea–hypopnea index (AHI) ≥5, insomnia as AIS≥6, and COMISA as the presence of both criteria. Comparative statistical analyses were performed between the OSA and COMISA groups. Results A total of 407 patients with COMISA (56.3% male; median age 55 years, IQR:46–65) and 218 with OSA (65.6% male; median age 58 years, IQR:48–66) were included. Significant differences were observed in age and sex distribution. COMISA patients exhibited markedly higher rates of excessive daytime sleepiness (EDS) (40.5% vs. 17.9%, p< 0.001), severe fatigue (63.6% vs. 25.7%, p< 0.001), and increased prevalence of clinically significant anxiety (45% vs. 12.4%, p< 0.001) and depressive symptoms (48.6% vs. 18.3%, p< 0.001) compared with the OSA group. Conclusion Findings demonstrate that COMISA is associated with substantial daytime symptomatology and psychological distress, exceeding that seen in OSA alone. Individuals with insomnia and OSA show high rates of EDS and fatigue that in contrast to OSA alone appear to be a result of psychological distress and less the impact of COMISA on objective indices of sleep disturbance. These observations highlight COMISA as a distinct and clinically complex phenotype. A more holistic and individualized approach—integrating sleep-focused, behavioral, and psychological interventions—may improve diagnostic accuracy, treatment adherence, and overall outcomes. Support (if any)