IntroductionNight-shift workers often face various health issues stemming from circadian rhythm shift and the consequent poor sleep quality. We aimed to study nurses working night shifts, evaluate the electroencephalogram (EEG) pattern of daytime sleep, and explore possible pattern changes due to ambient light exposure (30 lux) compared to dim conditions (<5 lux) during daytime sleep.MoethodsThe study involved 31 participants who worked night shifts and 24 healthy adults who had never worked night shifts. The sleep macro and microstructures were analyzed, and electrophysiological activity was compared (1) between nighttime sleep and daytime sleep with dim light and (2) between daytime sleep with dim and 30 lux light conditions.ResultsThe daytime sleep group showed lower slow or delta wave power during non-rapid eye movement (NREM) sleep than the nighttime sleep group. During daytime sleep, lower sigma wave power in N2 sleep was observed under light exposure compared to no light exposure. Moreover, during daytime sleep, lower slow wave power in N3 sleep in the last cycle was observed under light exposure compared to no light exposure.DiscussionOur study demonstrated that night shift work and subsequent circadian misalignment strongly affect sleep quality and decrease slow and delta wave activities in NREM sleep. We also observed that light exposure during daytime sleep could additionally decrease N2 sleep spindle activity and N3 waves in the last sleep cycle.

中文翻译：

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夜班后光照对轮班护士白天睡眠有影响吗？：脑电图功率分析

简介夜班工人经常面临因昼夜节律变化以及由此导致的睡眠质量差而产生的各种健康问题。我们的目的是研究夜班护士，评估白天睡眠的脑电图 (EEG) 模式，并探索与白天睡眠期间的昏暗条件 (<5 lux) 相比，环境光暴露 (30 勒克斯) 可能导致的模式变化。涉及 31 名上夜班的参与者和 24 名从未上夜班的健康成年人。分析睡眠的宏观和微观结构，并比较（1）夜间睡眠和白天昏暗光线条件下的电生理活动以及（2）白天昏暗和30勒克斯光线条件下睡眠之间的电生理活动。结果白天睡眠组表现出较低的慢波或δ波非快速眼动 (NREM) 睡眠期间的功率高于夜间睡眠组。在白天睡眠期间，与无光照射相比，在 N2 睡眠中观察到光照射下的西格玛波功率较低。此外，在白天睡眠期间，与无光照射相比，在有光照射下，最后一个周期的 N3 睡眠中的慢波功率较低。讨论我们的研究表明，夜班工作和随后的昼夜节律失调会严重影响睡眠质量，并减少慢波和 δ 波活动在非快速眼动睡眠中。我们还观察到，白天睡眠期间的光照还会降低最后一个睡眠周期的 N2 睡眠纺锤体活动和 N3 波。