The quality of life of suspected obstructive sleep apnea patients is related to their subjective sleep quality rather than the apnea-hypopnea index
OBJECTIVE Insomnia symptoms are prevalent in subjects with obstructive sleep apnea syndrome (OSA) and are important risk factors for suicidal ideation (SI). However, the significance of SI has not been clearly demonstrated in persons with both OSA and insomnia. We aimed to investigate the prevalence of SI and its relationship with insomnia symptoms, mood, and other relevant factors. METHODS A total of 117 consecutive subjects with untreated OSA (apnea-hypopnea index ≥5/h) participated in the study. They completed questionnaires regarding SI ([BDI-II], item 9), insomnia symptoms (Insomnia Severity Index [ISI]), depressive mood (modified BDI-II [mBDI-II], which excluded items on SI and sleep disturbances), dysfunctional beliefs and attitudes about sleep (DBAS), social support, and quality of life. RESULTS The overall prevalence of SI was 20.5% in subjects with OSA. A total of 32 subjects (27.4%) reported significant insomnia symptoms (ISI ≥ 15). Higher SI was associated with higher scores on ISI, DBAS, and mBDI-II and lower scores on social support and quality of life questionnaires. The severity of insomnia was positively correlated with depressive mood. The relationship between SI and insomnia severity was insignificant after adjusting for depressive symptom severity. CONCLUSION Patients with OSA may have SI and insomnia symptoms. Collinearity was observed between sleep and mood disturbances. Yet, it is remarkable to find a significant association between OSA and SI, which are additional contributions to insomnia. This study suggests the necessity of integrated approaches to SI and related factors for the comprehensive treatment of OSA.