0880 THE INFLUENCE OF SLEEP DISORDERED BREATHING SEVERITY ON CEREBRAL OXYGENATION IN CHILDREN

Abstract

Sleep disordered breathing (SDB) is a common paediatric sleep disorder ranging in severity from primary snoring (PS) to obstructive sleep apnoea (OSA). Children with PS by definition do not experience clinically significant desaturation or sleep fragmentation, whereas OSA is characterized by repetitive hypoxia, hypercarbia and sleep fragmentation. Both hypoxia and sleep disruption are thought to impact neurocognitive development. Near-infrared spectroscopy measures tissue oxygenation index (TOI) which represents cerebral oxygenation. To date there have been few studies examining the effects of SDB on TOI in children and they have not distinguished between severities of OSA. The aim of this study was to determine the effect of SDB severity on TOI in children. 139 children aged 3–12 y underwent overnight polysomnography and were classified as having PS (obstructive apnoea hypopnoea index (OAHI) ≤1 event per hour; n=31), mild OSA (>1 OAHI ≤5 events per hour; n=38), moderate/severe OSA (MS) OSA (OAHI >5 events per hour; n=30) or non-snoring controls recruited from the community (n=40). One-way analysis of variance (ANOVA) with Bonferroni post hoc testing was used to compare severity groups in each sleep state. Pearson correlations were performed to assess the relationship between OAHI and TOI during wake, N1, N2, N3, REM and total sleep for the cohort as a whole. Results are presented as mean±SEM. During wake, TOI was significantly lower in controls (72.5 ± 0.6%) compared to PS (75.0 ± 0.6%) and MS OSA (75.0 ± 0.5%), p<0.05 for both. Though not reaching statistical significance, all severities of SDB had elevated TOI compared to controls during the different sleep stages. When the entire cohort was analysed, there was no correlation between OAHI and TOI in any sleep stage. Our study has demonstrated that children with SDB have elevated cerebral oxygenation compared to healthy non-snoring controls during wake. This may be due to a protective mechanism influenced by other physiological parameters such as elevated blood pressure, which is evident in children with SDB, acting to conserve cerebral oxygenation levels. National Health and Medical Research Council of Australia Project APP1063500. Victorian Government’s Research Infrastructure Support Program.