Pedersen Torhild T, Sunde Erlend, Wisor Jonathan, Mrdalj Jelena, Pallesen Ståle, Grønli Janne
Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, Bergen, Norway.
Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway.
Nat Sci Sleep. 2022 Feb 18;14:243-254. doi: 10.2147/NSS.S339639. eCollection 2022.
Millions of people work at times that overlap with the habitual time for sleep. Consequently, sleep often occurs during the day. Daytime sleep is, however, characterized by reduced sleep duration. Despite preserved time spent in deep NREM sleep (stage N3), daytime sleep is subjectively rated as less restorative. Knowledge on how night work influences homeostatic sleep pressure is limited. Therefore, we aimed to explore the effect of three consecutive simulated night shifts on daytime sleep and markers of sleep homeostasis.
We performed continuous EEG, EMG and EOG recordings in the subjects' home setting for one nighttime sleep opportunity, and for the daytime sleep opportunities following three consecutive simulated night shifts.
For all daytime sleep opportunities, total sleep time was reduced compared to nighttime sleep. While time spent in stage N3 was preserved, sleep pressure at sleep onset, measured by slow wave activity (1-4 Hz), was higher than nighttime sleep and higher on day 3 than on day 1 and 2. Elevated EEG power during daytime sleep was sustained through 6 h of time in bed. Slow wave energy was not significantly different from nighttime sleep after 6 h, reflecting a less efficient relief of sleep pressure.
Adaptation to daytime sleep following three consecutive simulated night shifts is limited. The increased homeostatic response and continuation of sleep pressure relief even after 6 h of sleep, are assumed to reflect a challenge for appropriate homeostatic reduction to occur.
数以百万计的人在与习惯性睡眠时间重叠的时段工作。因此，睡眠常常发生在白天。然而，白天睡眠的特点是睡眠时间缩短。尽管深度非快速眼动睡眠（N3期）的时长保持不变，但白天睡眠的主观恢复感较差。关于夜间工作如何影响睡眠稳态压力的知识有限。因此，我们旨在探讨连续三个模拟夜班对白天睡眠和睡眠稳态标志物的影响。
我们在受试者家中进行连续脑电图（EEG）、肌电图（EMG）和眼电图（EOG）记录，记录一次夜间睡眠机会以及连续三个模拟夜班后的白天睡眠机会。
与夜间睡眠相比，所有白天睡眠机会的总睡眠时间均减少。虽然N3期的时长保持不变，但通过慢波活动（1 - 4赫兹）测量的睡眠开始时的睡眠压力高于夜间睡眠，且在第3天高于第1天和第2天。白天睡眠期间升高的脑电图功率在卧床6小时内持续存在。6小时后慢波能量与夜间睡眠无显著差异，这反映出睡眠压力缓解效率较低。
连续三个模拟夜班后对白天睡眠的适应是有限的。即使在睡眠6小时后，睡眠稳态反应增加且睡眠压力缓解仍在持续，这被认为反映了适当的睡眠稳态降低所面临的挑战。
