Objective: To explore the effect of arousal parameters on excessive daytime sleepiness(EDS) in patients with obstructive sleep apnea syndrome(OSAS).
Methods: A total of 205 patients who underwent polysomnography (PSG) from June 2012 to September 2013 in our hospital were enrolled. They were divided into 3 groups:85 patients in the OSAS sleepiness group (AHI ≥ 5/h, ESS ≥ 9), 86 patients in the OSAS non-sleepiness group (AHI ≥ 5/h, ESS<9), and 34 healthy subjects in the control group (AHI<5 times/h, ESS<9). Patient characteristics and PSG parameters of the 3 groups were analyzed.
Results: The difference of age, BMI, ESS, N1+ N2%, N3%, AHI, oxygen desaturation index (ODI), mean oxygen saturation (MSaO₂), lowest oxygen saturation (LSaO₂), oxygen below 90% of the time (T90%), total arousal index (ARtotI), respiratory arousal index/ARtotI (RAI/ARtotI), spontaneous arousal index/ARtotI (SAI/ARtotI), sleep pressure score (SPS) were statistically different among the 3 groups (P < 0.05). But except for REM% [(15 ± 5)%, (16 ± 6)%, (17 ± 7)%, P > 0.05], the difference of age and BMI between OSAS sleepiness group and OSAS non-sleepiness group were not significant (P > 0.016 7), but the difference of other indices between any 2 groups were significant (P < 0.016 7). ARtotI and SPS were positively correlated with ESS (r = 0.383 and 0.244, P < 0.001). Logistic regression analysis showed that only awakening and SPS were the risk factors for OSAS [OR = 1.070 (95% CI: 1.038 - 1.102) and 0.158 (95% CI: 0.026 - 0.984), respectively].
Conclusions: Arousal at night is closely associated with EDS in OSAS. ARtotI and SPS can be evaluated as an objective indicator of EDS in OSAS patients.