BACKGROUND: The aim of this study was to evaluate the relationship between the duration of arousal and the type, duration and minSaO(2) of apneas/hypopneas, and the time of night and sleep stage when they occurred. MATERIAL/ METHODS: We measured the duration of arousals associated with apneas (A) and hypopneas (H) in 10 polysomnographic recording. Arousals were categorized as: 1) Short Electroencephalographic Arousal (SEA: 3-15 s) and 2) Awakenings (>15 s). The dependent variable for multiple logistic regression analysis was duration of arousal (0 = 3-11 s, 1 = >11 s); the independent variables were event (0 = H, 1 = A), event duration (0 = 10-20 s, 1 = >20 s), sleep stage (0 = REM, 1 = NREM 1-2); minSaO(2) (0 = 86%, 1 = <86%) and time of night (0 = at or before 3:00 AM, 1 = after 3:00 AM). RESULTS: We analyzed 1536 apneas and hypopneas. 80.3% had arousal, 61% SEA and 19.3% awakenings. The median duration of arousal was higher in apneas (A: 12 s, H: 9.2 s, p<0.001). The apneas and events >20 s with a minSaO(2) <86% had a higher probability of arousal >11 s (apnea: OR 2.1, p<0.001; events >20 s: OR 1.5, p<0.01; minSaO(2) <86%: OR 1.4, p<0.05). CONCLUSIONS: Arousals were greater in apneas than in hypopneas. Apneas and events >20 s with a minSaO(2) <86% were associated more frequently with arousal >11 s.
BACKGROUND: The aim of this study was to evaluate the relationship between the duration of arousal and the type, duration and minSaO(2) of apneas/hypopneas, and the time of night and sleep stage when they occurred. MATERIAL/ METHODS: We measured the duration of arousals associated with apneas (A) and hypopneas (H) in 10 polysomnographic recording. Arousals were categorized as: 1) Short Electroencephalographic Arousal (SEA: 3-15 s) and 2) Awakenings (>15 s). The dependent variable for multiple logistic regression analysis was duration of arousal (0 = 3-11 s, 1 = >11 s); the independent variables were event (0 = H, 1 = A), event duration (0 = 10-20 s, 1 = >20 s), sleep stage (0 = REM, 1 = NREM 1-2); minSaO(2) (0 = 86%, 1 = <86%) and time of night (0 = at or before 3:00 AM, 1 = after 3:00 AM). RESULTS: We analyzed 1536 apneas and hypopneas. 80.3% had arousal, 61% SEA and 19.3% awakenings. The median duration of arousal was higher in apneas (A: 12 s, H: 9.2 s, p<0.001). The apneas and events >20 s with a minSaO(2) <86% had a higher probability of arousal >11 s (apnea: OR 2.1, p<0.001; events >20 s: OR 1.5, p<0.01; minSaO(2) <86%: OR 1.4, p<0.05). CONCLUSIONS: Arousals were greater in apneas than in hypopneas. Apneas and events >20 s with a minSaO(2) <86% were associated more frequently with arousal >11 s.