阻塞性睡眠呼吸暂停患者睡眠脑电慢波活动的特征

Characteristic of slow wave activity in electroencephalogram during overnight sleep in patients with obstructive sleep apnea

目的探讨阻塞性睡眠呼吸暂停(OSA)患者睡眠脑电慢波活动(SWA)的特征。方法回顾性分析在四川大学华西医院睡眠中心以打鼾为主诉并完成整夜多导睡眠图(PSG)监测的77例患者的临床资料,其中男31例,女46例,年龄(55.3±5.2)岁;依据呼吸暂停低通气指数(AHI)分为4组:单纯打鼾组(AHI<5次/h)、轻度OSA组(5次/h≤AHI<15次/h)、中度OSA组(15次/h≤AHI<30次/h)、重度OSA组(AHI≥30次/h),分别在整夜睡眠期、非快速眼动(NREM)期和快速眼动(REM)期中,先比较各组间5个频带的绝对脑电能量;然后比较4组SWA的相对值在NREM周期的分布;并进一步分析所有受试者中SWA与AHI及Epworth嗜睡量表(ESS)评分的相关性。结果在整夜睡眠期、NREM期和REM期,中度和重度OSA组的SWA均低于轻度OSA和单纯打鼾组[整夜睡眠期:(120.3±49.4)、(125.6±65.5)比(147.1±68.3)、(163.1±66.7)μV2,NREM期:(143.9±60.0)、(146.6±77.1)比(173.6±79.8)、(193.7±82.4)μV2,REM期:(39.9±14.7)、(41.4±13.1)比(48.4±20.8)、(52.6±21.7)μV2],但差异均无统计学意义(均P>0.05);从第1个NREM周期到第4个NREM周期,各组的SWA相对值均呈减小趋势。单纯打鼾组、轻度及中度OSA组4个NREM周期间的相对SWA差异均有统计学意义(均P<0.001),重度OSA组在4个NREM周期的相对SWA分别为(156.5±0.5)%、(149.6±±0.4)%、(135.1±0.4)%、(121.7±0.4)%(P=0.053);在第4个NREM周期,重度OSA组的相对SWA高于轻度OSA组[(85.5±0.3)%比(121.7±0.4)%](P=0.004);第1个NREM周期SWA与ESS评分负相关(r=-0.239,P=0.043),整夜SWA、NREM期SWA、REM期SWA及4个NREM周期SWA与AHI均无相关性(r=-0.095、-0.092、-0.174、-0.161、-0.089、-0.024、-0.115,均P>0.05)。结论OSA患者的SWA有内在稳定性,且与患者的日间嗜睡程度有关,是评估OSA患者日间嗜睡程度的潜在指标;SWA作为睡眠质量评价指标在临床应用时,应注意动态分析,关注其周期性变化。

Objective To characterize electroencephalogram(EEG)power in different frequency bands,particularly in overnight distribution of slow wave activity(SWA)in patients with obstructive sleep apnea(OSA).Methods Seventy-seven subjects[31 males and 46 females,aged(55.3±5.2)years]with primary complaint of snoring from Sleep Medicine Center of West China Hospital were included in the study.All subjects underwent one night polysomnography(PSG).The subjects were divided into four groups based on the apnea hypopnea index(AHI):primary snoring(AHI<5 times/h),mild OSA(5 times/h≤AHI<15 times/h),moderate OSA(15 times/h≤AHI<30 times/h),and severe OSA(AHI≥30 times/h).The absolute EEG power values across five frequency bands during overnight sleep,during non-rapid eye movement(NREM)and rapid eye movement(REM)sleep periods were initially compared across four groups.Afterwards,the relative SWA values over four NREM cycles during overnight records were compared across four groups,and the correlation between SWA and AHI,Epworth sleepiness scale(ESS)score was analyzed among all subjects.Results For overnight analysis,SWA in the moderate and severe OSA groups was lower than that in the mild OSA and primary snoring groups during total sleep,NREM and REM periods[total sleep:(120.3±49.4),(125.6±65.5)vs(147.1±68.3),(163.1±66.7)μV2;NREM period:(143.9±60.0),(146.6±77.1)vs(173.6±79.8),(193.7±82.4)μV2;REM period:(39.9±14.7),(41.4±13.1)vs(48.4±20.8),(52.6±21.7)μV2],but did not reach the significant level(all P>0.05).Four groups showed decreased patterns in relative SWA values from the first NREM cycle to the fourth NREM cycle.The relative SWA had significant difference among four NREM cycles in the primary snoring group,mild and moderate OSA groups(all P<0.001).In the severe OSA group,the relative SWA in four NREM cycles respectively was(156.5±0.5)%,(149.6±0.4)%,(135.1±0.4)%,(121.7±0.4)%(P=0.053).The relative SWA in the severe OSA group was higher than that in the mild OSA group in the fourth NREM cycle[(85.5±0.3)%vs(121.7±0.4)%](P=0.004).SWA in 1st NREM cycle was negatively correlated with ESS score(r=-0.239,P=0.043),no correlation was found between overnight SWA,SWA in NREM period,SWA in REM period,SWA in four NREM cycles and AHI(r=-0.095,-0.092,-0.174,-0.161,-0.089,-0.024,-0.115,all P>0.05).Conclusions The results suggest that SWA in OSA patients has internal stability and is related to daytime sleepiness.SWA is a potential predictor of daytime sleepiness in OSA patients.When SWA is used as a clinical indicator of sleep quality,attention should be paid to the dynamic analysis and its periodic changes.