Polysomnographic findings and psychiatric symptoms in patients with comorbid insomnia and sleep apnea: a retrospective study focusing on sex differences

Purpose: Comorbid insomnia and obstructive sleep apnea (COMISA) present significant clinical challenges, given their overlapping symptoms and detrimental effects on health. Only a few studies have explored sex differences in patients with obstructive sleep apnea (OSA) and COMISA. This retrospective study investigated sex differences in psychiatric symptoms and polysomnographic findings between patients with COMISA and those with OSA alone.

Methods: Patients who underwent polysomnography (PSG) and completed questionnaires at a single tertiary hospital sleep center were enrolled. Patients diagnosed with OSA using PSG (apnea-hypopnea index ≥ 5) were categorized based on the Insomnia Severity Index-Korean version (ISI) into OSA without insomnia (OSA-only group; ISI < 15) and OSA with insomnia (COMISA group; ISI ≥ 15).

Results: This study included 1,096 adult patients diagnosed with OSA, of whom 426 (38.9%) were in the COMISA group. COMISA was more common in women than in men (50.7% vs. 34.5%, p < 0.001). The COMISA group reported more severe subjective psychiatric symptoms, including depression, anxiety, and daytime sleepiness in both men and women. The male COMISA group had lower sleep efficiency (p = 0.02) and longer sleep latency (p = 0.002) than those had by the OSA-only group. The male COMISA group had a higher apnea-hypopnea index (p = 0.04) and a lower mean oxygen saturation (p = 0.004) than those had by the OSA-only group.

Conclusion: These findings highlight the importance of considering sex-specific clinical and polysomnographic characteristics when managing patients with COMISA.