EFFECT OF PARTIAL DEPRIVATION ON BOTH DAYTIME VIGILANCE MEASURES AND NOCTURNAL RESPIRATORY DISORDER VARIABLES IN OBSTRUCTIVE SLEEP APNEA SYNDROME

众所周知，睡眠不足既会增加白天的嗜睡感，又会减少上呼吸道扩张肌的张力。然而，早期部分睡眠剥夺对阻塞性睡眠呼吸暂停综合征（OSAS）患者日间警觉性和夜间呼吸障碍测量的影响尚未得到很好的阐明。为了澄清这一问题，我们对早期部分睡眠剥夺对OSAS患者日间功能指标和夜间睡眠变量的影响进行了一系列研究。本研究的受试者包括10名未经治疗的OSAS受试者（M:F=7:3，平均年龄29.7±3.4岁）和10名健康的正常对照（M:F=8:2, 29.8±4.5岁），他们的睡眠时间正常，维持清醒试验（MWT）的平均睡眠潜伏期值正常（20分钟法，12分钟或以上）。在两周满意的夜间睡眠后，受试者在正常睡眠状态（0:00 - 7:00睡眠）和早期部分睡眠剥夺状态（SD，睡眠时间限制在3:00 - 7:00）下进行多导睡眠图记录（PSG），随后进行日间警觉性检查，包括MWT、精神运动警觉性测试（PVT）和事件相关电位（P300）。以随机交叉的方式将这些条件的顺序分配给所有受试者。对比SD 3天正常状态与恢复夜的PSG夜间睡眠结构，两组睡眠潜伏期均高于正常状态，恢复夜的%阶段REM和睡眠潜伏期均小于正常状态。在呼吸障碍变量方面，两组在恢复夜呼吸暂停低通气指数均较高。然而，只有在OSAS组中，呼吸暂停和低通气发作时间明显延长，恢复夜夜间经皮氧饱和度（SaO2）明显升高。在日间心理生理指标中，SD条件下两组P300潜伏期均显著延长。另一方面，在这种情况下，P300的振幅值较小，仅在OSAS组被识别出来。在PVT变量方面，只有OSAS组的反应延迟和错误反应的数量显著增加。在MWT方面，SD条件下被试两组的平均睡眠潜伏期明显短于正常条件。然而，与健康对照组相比，OSAS组的SD潜伏期下降率显著高于健康对照组。综上所述，OSAS组夜间呼吸障碍变量的恶化，特别是呼吸事件的延长导致恢复期夜间氧饱和度的加重更为突出。此外，与健康组相比，OSAS组在SD期间以MWT估计的客观日间嗜睡增加、P300表现的大脑信息加工和PVT表现的警觉性依赖精神运动功能的恶化更为明显。这些发现强烈地表明，即使是三天的部分睡眠剥夺也会加重呼吸系统疾病本身和白天嗜睡以及相关的精神运动功能障碍，特别是在OSAS患者中。我们想强调OSAS早期治疗的必要性以及在这类患者中保持正确睡眠卫生的意识。少

It has been well known that sleep deprivation brings both elevation of daytime sleepiness and decrease in the tonus of upper airway dilating muscles. However, influence of early partial sleep deprivation on the daytime vigilance and nocturnal respiratory disorder measures in obstructive sleep apnea syndrome (OSAS) has not been well elucidated. In order to clarify this issue, we made a series of the study on the effect of early partial sleep deprivation on the daytime functioning measures and nocturnal sleep variables of OSAS patients.Subjects of this study comprised of both ten untreated OSAS subjects (M:F=7:3, mean age with 29.7 ±3.4 years) and 10 healthy normal controls (M:F=8:2, 29.8±4.5 years) with both normal sleep schedule and normal values of mean sleep latency of maintenance of wakefulness test (MWT) (20 minutes method ; 12 minutes or above). After two weeks of satisfactory nocturnal sleep, the subjects underwent polysomnographic recording (PSG) followed by daytime vigilance ex … More amination including MWT, psychomotor vigilance test (PVT) and event related potentials (P300) under normal sleep condition (subjects slept during the period from 0:00 to 7:00) and condition with early partial sleep deprivation (SD ; sleep period was restricted to the period from 3:00 to 7:00). Order of these conditions was assigned to all the subjects with randomized cross over manner.When comparison of nocturnal sleep structure on PSG between normal condition and recovery night from three days of SD, both group showed higher values of sleep latency and smaller values of both % stage REM and sleep latency on recovery night compared with those on the night of normal condition. As for respiratory disorder variables, both groups showed higher values of apnea hypopnea index on the recovery night. However, significant prolongation of episodes of both apnea and hypopnea as well as significant increase in the nocturnal percutaneous oxygen desaturation(SaO2) on the recovery night was recognized only in the group with OSAS. Among daytime psychophysiological measures, latency of P300 was significantly longer under SD condition in both groups. On the other hand, smaller value of the amplitude of P300 under that condition was recognized only in the group with OSAS. With respect to PVT variables, significant increase in the number of both reaction lapse and false response with SD was recognized only in the group with OSAS. Regarding MWT, mean sleep latency was significantly shorter under SD condition compared with normal condition in the subject two groups. However, rate of decrease in the latency during SD was significantly higher in the group with OSAS compared with healthy control group.From these results, it was revealed that worsening of nocturnal respiratory disorder variables especially prolongation of respiratory events leading to the aggravation of nocturnal oxygen desaturation on the recovery night was more prominent in the group with OSAS. Moreover, increase in objective daytime sleepiness estimated with MWT and deterioration of both cerebral information process manifested on P300 as well as vigilance dependent psychomotor function manifested on PVT during SD was more marked in the OSAS group than in the healthy group. These findings strongly impress that partial sleep deprivation even for three days could act to aggravate respiratory disorder itself and daytime sleepiness as well as its related psychomotor dysfunctioning especially in OSAS patients. We want to emphasize the necessity of both the early treatments of OSAS and the awareness of maintaining correct sleep hygiene in this patients population. Less