Aim: To determine the association between body position and obstructive events during sleep as determined by polysomnography (PSG) in infants of ages 8-12 months with obstructive sleep apnea (OSA).
Methods: Consecutive nocturnal polysomnograms (NPSGs) of 50 children ages 8-12 months old referred to the sleep disorders center between 1 January 2003 and 1 June 2006 for possible sleep-disordered breathing were retrospectively reviewed. Data on total obstructive apnea index (AI), total obstructive apnea-hypopnea index (AHI), AI by body position, AHI by body position, rapid eye movement (REM) and non-REM sleep AHI and REM and non-REM AI were recorded.
Results: The mean age was 9.5+/-1.9S.D. months and 46% of the patients were females. There were no significant differences between the mean non-supine AHI (2.0+/-5.1) and supine AHI (2.5+/-5.4), p=0.63. When comparing specific body positions, there were also no significant differences between the mean supine AHI (2.5+/-5.4), prone AHI (2.9+/-7.3), left-lateral decubitus AHI (1.1+/-6.1), or the right-lateral decubitus AHI (2.5+/-7.6), p=0.71. Additionally, there were also no significant differences between the mean non-supine AI (0.7+/-2.9) and supine AI (1.4+/-3.0), p=0.23, and no differences between the supine AI (0.7+/-2.9), prone AI (1.0+/-2.9), left-lateral decubitus AI (0.3+/-2.9) or the right-lateral decubitus AI (1.1+/-3.0), p=0.44. Children spent an average of 50% of their total sleep time supine. OSA was significantly worse in REM sleep as compared to non-REM sleep (REM AHI 4.3+/-7.3 versus non-REM AHI 1.4+/-3.9, p=0.015; REM AI 5.1+/-4.9 versus non-REM AI 1.5+/-4.9, p<0.001). Mean time in REM sleep was 26% (range 5-42%).
Conclusions: There was no significant effect of body position on sleep-disordered breathing in 8-12 months old infants, although REM sleep represented a significant risk factor for OSA.