Sleep disturbance in pre-school children with obstructive sleep apnoea syndrome

Study objectives: Sleep-disordered breathing in children is most prevalent in the pre-school years and has been associated with sleep fragmentation and hypoxia. We aimed to compare the sleep and spontaneous arousal characteristics of 3-5-year-old children with obstructive sleep apnoea (OSA) with that of non-snoring control children, and to further characterise the arousal responses to obstructive respiratory events. Methods: A total of 73 children (48 male) underwent overnight polysomnography: 51 for assessment of snoring who were subsequently diagnosed with OSA (obstructive apnoea hypopnoea index (OAHI) > 1 event per h) and 22 control children recruited from the community (OAHI <= 1 and no history of snoring). Results: The OSA group had poorer sleep efficiency (p < 0.05), spent a smaller proportion of their sleep period time in rapid eye movement (REM) (p < 0.05), and had significantly fewer spontaneous arousals (p < 0.001) compared with controls. One-quarter of the children with OSA had a sleep pressure score above the cut-off point for increased sleep pressure. In children with OSA, 62% of obstructive respiratory events terminated in a cortical arousal and 21% in a sub-cortical arousal. A significantly higher proportion of obstructive respiratory events terminated in a cortical arousal during non-REM (NREM) compared with REM (p < 0.001). Conclusions: These findings suggest that in pre-school children OSA has a profound effect on sleep and arousal patterns. Given that these children are at a critical period for brain development, the impact of OSA may have more severe consequences than in older children. (C) 2011 Elsevier B.V. All rights reserved.