Cyclic Alternating Pattern in Obstructive Sleep Apnea Patients with versus without Excessive Sleepiness.

Area of Science:

• Sleep Medicine
• Neurology
• Pulmonology

Background:

• Excessive sleepiness (ES) in obstructive sleep apnea (OSA) is hypothesized to stem from increased arousal.
• Cyclic alternating pattern (CAP) reflects sleep microstructure, distinct from arousal.
• Investigating CAP in OSA patients with and without ES is crucial for understanding sleep disturbances.

Purpose of the Study:

• To compare sleep macro- and microstructure between OSA patients with and without ES.
• To identify variables associated with Epworth Sleepiness Scale (ESS) scores in OSA patients.

Main Methods:

• Thirty-eight male patients with moderate to severe OSA were divided into two groups based on ESS scores (ES vs. non-ES).
• Sleep macrostructure and microstructure (including CAP analysis) were assessed for both groups.

Main Results:

• No significant differences in clinical characteristics or sleep macrostructure were found between the ES and non-ES groups.
• The ES group showed significantly higher CAP rate, CAP duration, and number of CAP cycles, including subtype A2.
• The ES group had a lower mean phase B duration, but ESS scores did not correlate with CAP measures.

Conclusions:

• OSA patients experiencing excessive sleepiness demonstrate altered sleep microstructure characterized by increased CAP.
• CAP measures, rather than arousal, may be more indicative of sleep disturbance in OSA patients with ES.