Research Information System
Sleep and Breathing, vol.30, no.2, 2026 (SCI-Expanded, Scopus)
Background: Obesity hypoventilation syndrome (OHS) frequently coexists with obstructive sleep apnoea (OSA), but the prevalence of comorbid insomnia and sleep apnoea (COMISA) in patients with OHS is uncertain. We aimed to determine COMISA prevalence in OHS and to describe the associated clinical and polysomnographic features. Methods: Adults with OSA ± OHS were included. Demographics, comorbidities, daytime arterial blood gases, polysomnography variables, structured sleep-questionnaire responses, and the Epworth Sleepiness Scale (ESS) score were noted. Results: We analysed 3,215 patients (516 with OHS, 2,699 with pure OSA; age:50.3 ± 12.0 years; female/male: 1,030/2,185). The prevalence of COMISA was higher in OHS than in pure OSA (32.0% vs. 22.6% p < 0.001). Within the OHS group, COMISA was associated with a higher apnoea–hypopnoea index, oxygen desaturation index, arousal index, and ESS score (all p < 0.001), as well as a higher prevalence of hypertension, diabetes mellitus, and heart failure (p < 0.001, p = 0.002, and p = 0.005, respectively). OHS patients with COMISA also had more severe OSA than COMISA patients alone did (p < 0.001). COMISA in OHS patients was independently associated with higher daytime arterial partial pressure of carbon dioxide (PaCO₂) (adjusted OR [aOR] 1.299; 95% CI 1.198–1.409; p < 0.001), more severe OSA (aOR 2.419; 95% CI 1.288–4.543; p = 0.006), higher ESS score (aOR 1.104; 95% CI 1.047–1.163; p < 0.001). Conclusions: Compared with pure OSA group, COMISA is more common in OHS. High daytime PaCO₂ was independently associated with COMISA in OHS. OHS patients with COMISA also had more fragmented sleep, greater OSA severity, a higher ESS score and a higher prevalence of comorbidities.