O029 Sleep architecture differs for individuals manifesting excessive daytime sleepiness with and without obstructive sleep apnea

Abstract Introduction The mechanism underlying the development of excessive daytime sleepiness (EDS) in obstructive sleep apnea (OSA) remains unclear. Thus, we characterised association between architecture and EDS individuals with without OSA. Methods 1876 suspected OSA patients reporting underwent in-lab polysomnography next-day multiple latency test (MSLT). We investigated characteristics (apnea-hypopnea index [AHI]≥5, n=1508) non-OSA (AHI<5, n=368) (MSLT≤10-minutes MSLT>10-minutes). Sleep was quantified by N1, N2, N3, REM, total time (TST), wake after onset (WASO). Results had less N1 (median: 10.0 vs 12.0-minutes, p<0.05) N3 (60.2 71.5-minutes, sleep, WASO (43.0 51.0-minutes, p<0.05), more N2 (210.5 189.0-minutes, higher TST (365.0 351.5-minutes, than non-EDS patients. No difference observed amount REM (70.0 67.5-minutes, p=0.46) sleep. Non-OSA (31.5 40.0-minutes, (188.5 177.5-minutes, (374.5 359.0-minutes, (76.5 68.5-minutes, Discussion While associated greater both groups, there also characteristic differences. have duration, while There is likely a complex bi-directional relationship reflecting acute/chronic disruption compensatory mechanisms.