Obstructive sleep apnea may induce sleep-wake cycle dysregulation: An actigraphic study

Area of Science:

• Sleep Medicine
• Chronobiology
• Neurology

Background:

• Obstructive sleep apnea (OSA) is associated with sleep fragmentation and excessive daytime sleepiness (EDS).
• Circadian rhythm dysregulation is hypothesized to worsen OSA-related diurnal symptoms.
• Understanding the relationship between sleep-wake rhythm and EDS in OSA is crucial.

Purpose of the Study:

• To assess the sleep-wake rhythm using actigraphy in patients with untreated OSA.
• To investigate the relationship between actigraphy-measured sleep-wake rhythm parameters and EDS in OSA patients.
• To compare sleep-wake rhythm and diurnal symptoms between OSA patients and healthy controls (HC).

Main Methods:

• A 7-day actigraphic recording was performed on moderate-to-severe OSA patients (apnea-hypopnea index ≥15/h) and HC.
• Participants completed questionnaires for EDS (Epworth sleepiness scale, ESS), sleep quality (Pittsburgh sleep quality index, PSQI), and chronotype (morningness-eveningness questionnaire, MEQ).
• Statistical analyses controlled for chronotype (MEQ scores) to compare sleep-wake parameters and symptom scores between groups.

Main Results:

• OSA patients exhibited lower sleep time, sleep efficiency, and a higher sleep latency and fragmentation compared to HC.
• Actigraphy revealed reduced average activity during the most active 10-hour period and a lower day/night activity ratio in OSA patients.
• OSA patients reported significantly higher ESS and PSQI scores, and a less morning chronotype than HC.

Conclusions:

• Patients with OSA demonstrate a dysregulated circadian sleep-wake rhythm, characterized by reduced diurnal motor activity and a diminished day/night activity ratio.
• This circadian rhythm dysregulation in OSA may be interconnected with excessive daytime sleepiness and reduced daytime functioning.
• Findings highlight the importance of addressing circadian rhythm disturbances in the management of OSA.