Mild obstructive sleep apnea tends to be associated with sleep state misperception

Objective: Sleep state misperception (SSM) is a disorder that is characterized by insomnia or excessive sleepiness without objective evidence of sleep disturbance. The cause of SSM has not yet been elucidated. This study aimed to explore sleep perception tendencies by comparing polysomnography (PSG) data and subjective sleep reports in patients with and without obstructive sleep apnea (OSA). Methods: We retrospectively analyzed 638 participants with PSG results. We classified the participants into three groups based on their OSA severity (non-OSA, n=174; mild OSA, n=214; moderate OSA, n=250), and compared the PSG parameters and various sleep questionnaires among the groups using an analysis of variance. Additionally, we identified the rapid eye movement (REM)-related OSA and compared the variables between the REM-related OSA and non-REM-related OSA groups using independent t and chi-square tests. Results: The participants with less severe OSA presented better quality and quantity of sleep in PSG (longer total sleep time, higher sleep efficiency, fewer arousals, and more deep sleep), but reported much worse sleep disturbances based on sleep questionnaires. Those with REM-related OSA showed a larger discrepancy between subjective and objective sleep. Conclusion: This study found that individuals with milder OSA and REM-related OSA tended to present larger discrepancies in objective and subjective sleep states. Further research based on our preliminary findings is warranted to better recognize SSM and treat complicated sleep disorders.