Abstract: Background　Obstructive sleep apnea-hypopnea syndrome （OSAHS） is one of the common sleep disorders.Previous studies demonstrate that change of sleep structure and decline of cognitive function are more likely to appear in older patients，with reasons incompletely determined yet.Up to now，there are few studies focusing on the relationship of the sleep electroencephalogram （EEG） and sleep structure with OSAHS patients at different ages.Objective　To explore the characteristics of sleep EEG of patients with severe OSAHS by age，so as to further provide significant information about brain plasticity change for instructing clinical treatment.Methods　In the study，67 patients definitely diagnosed with severe OSAHS from June 2017 to March 2018 in the Sleep Disordered Breathing Diagnosis and Therapy Center，Peking University Shenzhen Hospital were selected and were divided into the younger group （18-40 years old，n=34） and the older group （41-65 years old，n=33） based on the latest national age classification standard.We compared the two groups in the aspects of apnea-hypopnea index （AHI），the lowest SpO2 （LSpO2） during the night，sleep efficiency，the percentage of sleep time during various non-rapid eye movement （NREM） sleep stages （N1，N2 and N3），and the percentage of rapid eye movement （REM） sleep period in the total sleep time，electroencephalograph power density of various waves 〔EEG-δ （0.5-4.0 Hz），EEG-θ（4.1-8.0 Hz），EGG-α（8.1-12.0 Hz） and EGG-β （12.1-30.0 Hz）〕 during NREM period，and analyzed the correlation of electroencephalograph power density during NREM，sleep time in REM period and sleep efficiency with AHI.Results　As for the percentage of the sleep time during various stages in the total sleep time，it was higher during N1 and N2 stages in the older group than in the younger group，while was lower in N3 and REM period in the older group than in the younger group （P<0.05）.During the stages of N1，N2 and N3，the power densities of EEG-δ of patients in the older group were lower than those of patients in the younger group （P<0.05）.The power density of EEG-θ of patients in the older group was lower than that of those in the younger group during N3 stage （P<0.05）.During the stages of N2 and N3，the power densities of EEG-α of patients in the older group were lower than those of patients in the younger group （P<0.05）.During the stages of N1，N2 and N3，the power densities of EEG-β of patients in the older group were higher than those of patients in the younger group （P<0.05）.For the patients in the younger group，the correlation of the power density of EEG-δ，EGG-θ and EEG-α，the sleep time during REM period and the sleep efficiency with AHI was negative （r=-0.338，-0.315，-0.383，-0.483 and-0.501，respectively，P<0.05）；the power density of EEG-β during NREM period of younger group patients had no linearity correlation with AHI（P>0.05）.For the patients in the older group，the power density of various waves during NREM period，the sleep time during REM period and the sleep efficiency had no linearity correlation with AHI （P>0.05）.Conclusion　There are significant differences between the EEG performance of the younger and older patients with severe OSAHS.The older patients have longer N1 and N2-stage sleep time with shorter N3 and REM-sleep time；compared to the younger group，the EEG-δ during NREM period，EEG-θ and EEG-αduring N3 stage are found to decrease while EEG-β during NREM period is found to increase.All the EEG changes lead to the reduction of deep sleep time and the increase of shallow sleep time for the older patients with severe OSAHS.Consequently，they are easier to wake when coming across external stimuli and intermittent hypoxia，which directly lead to the increase of sleep fragmentation.

Key words: Sleep apnea syndromes, Brain waves, Sleep spindle wave, Rapid eye movement sleep, Non-rapid eye movement sleep

摘要： 背景　阻塞性睡眠呼吸暂停低通气综合征（OSAHS）是一种常见的睡眠障碍，既往研究表明，年长患者更容易出现睡眠结构的变化和认知功能下降，其原因尚未完全明确，且目前关于睡眠脑电波（EEG）和睡眠结构与不同年龄阶段OSAHS患者关系的研究较少。目的　探究不同年龄阶段重度OSAHS的EEG特征，旨在进一步为大脑可塑性变化提供重要信息，指导临床治疗。方法　选取2017年6月—2018年3月在北京大学深圳医院睡眠呼吸障碍疾病诊疗中心确诊的67例重度OSAHS患者，依据我国最新的年龄划分标准将其分为年轻组（18~40岁，n=34）和年长组（41~65岁，n=33）。比较两组患者呼吸暂停低通气指数（AHI）、夜间最低血氧饱和度（LSpO2）、睡眠有效率，非快速眼动睡眠（NREM）各分期（N1、N2、N3期）、快速眼动睡眠（REM）期睡眠时间占总睡眠时间百分比，NREM期各波〔δ波（0.5~4.0 Hz）、θ波（4.1~8.0 Hz）、α波（8.1~12.0 Hz）和β波（12.1~30.0 Hz）〕脑电能量密度；并分析两组患者NREM期各波脑电能量密度、REM期睡眠时间、睡眠有效率与AHI的相关性。结果　年长组患者N1期、N2期睡眠时间占总睡眠时间百分比大于年轻组，年长组患者N3期、REM期睡眠时间占总睡眠时间百分比小于年轻组（P<0.05）。年长组患者N1期、N2期、N3期δ波脑电能量密度均低于年轻组（P<0.05）。年长组患者N3期θ波脑电能量密度低于年轻组（P<0.05）。年长组患者N2期、N3期α波脑电能量密度低于年轻组（P<0.05）。年长组患者N1期、N2期、N3期β波脑电能量密度均高于年轻组（P<0.05）。年轻组患者NREM期δ波、θ波、α波脑电能量密度及REM期睡眠时间、睡眠有效率与AHI呈负相关（r值分别为-0.338、-0.315、-0.383、-0.483、-0.501，P值均<0.05）；年轻组患者NREM期β波脑电能量密度与AHI无直线相关关系（P>0.05）。年长组患者NREM期各波脑电能量密度、REM期睡眠时间和睡眠有效率与AHI无直线相关关系（P>0.05）。结论　重度OSAHS的年轻患者与年长患者的EEG存在明显差异，年长患者N1期、N2期睡眠时间较长，而N3、REM期睡眠时间较短；与年轻患者相比，年长患者NREM期的δ波、N3期的θ波和α波均减少，而NREM期的β波却明显增加。这些EEG的改变导致了重度OSAHS的年长患者深睡眠时间减少，而浅睡眠时间增加，外界的刺激及间歇性低氧更容易导致觉醒，直接导致睡眠片段化增加。

关键词: 睡眠呼吸暂停综合征, 脑电波, 睡眠纺锤波, 快速眼动睡眠, 非快速眼动睡眠