Sleep architecture and quality of life in comorbid OSA and depression: cross-sectional analysis of the Sydney sleep biobank

Introduction: Obstructive sleep apnoea (OSA) and depression are individually associated with changes in sleep architecture and reduced quality of life. However, there are few studies which report on the joint impact of comorbid OSA and depression. Methods: 821 participants from the Sydney Sleep Biobank database were assessed (38% female; age 49.5, SD 15.6 years). Participants were patients who were referred for and underwent an overnight sleep study on suspicion of sleep disordered breathing. Participants were divided into 4 groups based on the apnoea-hypopnoea index and depression score from the Depression Anxiety Stress Scale-21; (1) no OSA-no depression, (2) OSA-only, (3) depression-only, (4) comorbid OSA and depression (OSAD). Sleep architecture and quality of life (Epworth Sleepiness Scale, ESS and Functional Outcomes of Sleep, FOSQ-10) scores were compared between groups. Confounders considered included age, gender, body mass index, alcohol, and psychiatric medications. Results: Patients with OSAD and depression-only had higher ESS scores (8.4 vs 8.9 vs 6.9, p=0.003) and lower FOSQ-10 scores (13.9 vs 12.8 vs 16.7, p<0.001) than those with OSA-only. However, after control for confounders and excluding patients on psychiatric medications, OSAD was not associated with any significant changes in sleep architecture compared to those with OSA-only. Discussion/Conclusions: Despite the lack of changes in sleep architecture, it is still important to identify comorbid OSA and depression as it can be associated with worse quality of life and this may affect treatment compliance.