Body position and obstructive sleep apnea in 8-12-month-old infants

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 ± 1.9 S.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.