Sleep disruption and sleep position: Increased wake frequency in supine predicts lateral position preference

Area of Science:

• Sleep Medicine
• Physiology
• Biomechanics

Background:

• Individual preferences for sleep posture are not well understood.
• Physiological and biomechanical factors influencing sleep position preference require investigation.
• Understanding sleep posture mechanisms can inform interventions for sleep quality.

Purpose of the Study:

• To investigate the relationship between sleep position preference and position-specific sleep disturbances.
• To explore how biomechanical factors influence the choice between lateral and supine sleep positions.
• To identify physiological correlates of sleep posture preference.

Main Methods:

• Forty-one adults underwent two nights of at-home polysomnography on a firm mattress.
• Sleep architecture, position, and restlessness indices (limb movement, arousal, wake, respiratory, apnea-hypopnea) were measured.
• Linear mixed-effects regression analyzed associations between sleep position and restlessness.

Main Results:

• The supine position showed significantly increased restlessness indices compared to the lateral position.
• Respiratory arousals increased by 379%, arousal index by 108%, and wake index by 107% in the supine position.
• Higher wake index in supine sleep correlated with greater lateral sleep duration, and sleep preference was consistent across nights.

Conclusions:

• Individuals with a high wake index in the supine position demonstrate low tolerance for this posture.
• These individuals compensate by adopting the lateral sleep position more frequently.
• Biomechanical factors likely play a significant role in determining individual sleep posture preferences.