Mechanisms relating to sleeping position to the endotypes of sleep disordered breathing

Abstract

Purpose Obstructive sleep apnea (OSA) severity varies considerably depending on the body position during sleep in certain subjects. Such variability may be underpinned by specific, body position-related changes in OSA pathophysiological determinants, or endotypes. Also head position relative to trunk may influence OSA endotypes. However, no studies to our knowledge have reviewed the endotype variations according to head or body position up to now. Recent findings Several findings illustrate that supine OSA is mostly attributable to unfavorable upper airway anatomy compared to lateral position. However, a reduced lung volume, with consequent ventilatory instability (or elevated loop gain), may also play a role. Furthermore, preliminary findings suggest that prone and reclined positions may have a beneficial effect on collapsibility and loop gain. Summary Sleeping supine induces many unfavorable pathophysiological changes, especially in certain predisposed OSA patients. Little is known on the influence of other sleep positions on key endotypic traits.

Gender medicine and sleep disorders: from basic science to clinical research

“…In women, polygraphy of OSAS reflects these characteristics showing a lower AHI, shorter apneic episodes, reduced positional OSA ( 40 ), clustering of apneas during REM sleep ( 41 ), and prolonged nasal flow limitations indicating partial upper airway obstruction ( 42 ). Men and women display substantial sex differences in AHI during NREM sleep, with no significant variations during REM sleep.…”