Discordant Subjective Perception of Sleep in Patients with Obstructive Sleep Apnea and Insomnia: A Retrospective Study

BACKGROUND: Factors affecting subjective perception of sleep are unclear but clinically important. We investigated the differences in subjective sleep perception of patients with obstructive sleep apnea (OSA) and insomnia disorder (ID). MATERIAL/METHODS: From our Sleep Medicine Center database, 33 patients with OSA and 69 with ID were selected and assessed with the Pittsburgh Sleep Quality Index (PSQI), Generalized Anxiety Disorder screen, Patient Health Questionnaire-9, Epworth Sleepiness Scale, Pre-sleep Arousal Scale (PSAS), and polysomnography. RESULTS: In subjective sleep tests, PSQI total score, sleep quality, sleep onset latency (SOL), total sleep time, and sleep efficiency (SE) were higher in patients with ID. In objective sleep tests, patients with OSA had longer total sleep time, shorter SOL, lower percentage of stage N3, less SE, higher percentage of stage N1, more arousals, and higher arousal index. Hyperarousal state evaluation showed cognitive hyperarousal significantly higher with ID. Subjective sleep perception with OSA correlated positively with PSAS total score, cognitive hyperarousal, and percentage of stage N2 and negatively with percentage of REM, apnea-hypopnea index, and desaturation index. Subjective sleep perception of patients with ID correlated positively with PSAS total score, cognitive hyperarousal, SOL, N3 sleep latency, and REM sleep latency and negatively with SE. CONCLUSIONS: Subjective sleep perception of OSA patients was mainly related to sleep structure and respiratory events, and that of ID patients, to sleep latency. Individual cognitive hyperarousal levels may be involved in negative subjective sleep perception. Clinicians should be aware that OSA patients may not actually experience adequate sleep.