Body posture as a factor determining sleep quality in patients using non-invasive ventilation

Sleep quality is influenced by multiple factors. Slow-wave sleep and REM sleep play a key role in homeostasis and are useful indicators of sleep quality. Studies indicate that obstructive sleep apnea (OSA) in the supine position correlates with anatomical changes that exacerbate respiratory events and influence the effectiveness of ventilation therapy. This study aimed to evaluate the correlation of body posture with polysomnographic data and adherence of patients using continuous positive airway pressure (CPAP).

This was a retrospective study of patients with OSA who had polysomnography in Rainha Santa Isabel Hospital's sleep laboratory in Torres Novas, Portugal, and met all the inclusion and exclusion criteria. Sociodemographic, polysomnographic, and ventilation therapy variables were collected from that sleep laboratory database between 2015 and 2019.

In 30 patients with OSA, residual apnea-hypopnea index (AHIr) and arousal index were lower in the non-supine position compared to the supine position (p value 0.005 and 0.009 respectively). As measures of sleep quality, total sleep time in SWS and REM sleep were greater in the non-supine position compared to the supine position (p value of 0.002 and 0.010 respectively).

The findings suggest that a supine position significantly impairs sleep quality mainly by increasing the number of respiratory events and associated sleep fragmentation. The findings also suggest that the difference in AHIr between supine and non-supine positions may contribute to non-adherence with CPAP in patients with OSA.