Chang Anne-Marie, Aeschbach Daniel, Duffy Jeanne F, Czeisler Charles A
Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA 02115; Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115; and
Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA 02115; Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115; and Institute of Aerospace Medicine, German Aerospace Center, 51147 Cologne, Germany.
Proc Natl Acad Sci U S A. 2015 Jan 27;112(4):1232-7. doi: 10.1073/pnas.1418490112. Epub 2014 Dec 22.
In the past 50 y, there has been a decline in average sleep duration and quality, with adverse consequences on general health. A representative survey of 1,508 American adults recently revealed that 90% of Americans used some type of electronics at least a few nights per week within 1 h before bedtime. Mounting evidence from countries around the world shows the negative impact of such technology use on sleep. This negative impact on sleep may be due to the short-wavelength-enriched light emitted by these electronic devices, given that artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock. A few reports have shown that these devices suppress melatonin levels, but little is known about the effects on circadian phase or the following sleep episode, exposing a substantial gap in our knowledge of how this increasingly popular technology affects sleep. Here we compare the biological effects of reading an electronic book on a light-emitting device (LE-eBook) with reading a printed book in the hours before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock, and reduced next-morning alertness than when reading a printed book. These results demonstrate that evening exposure to an LE-eBook phase-delays the circadian clock, acutely suppresses melatonin, and has important implications for understanding the impact of such technologies on sleep, performance, health, and safety.
在过去50年里，平均睡眠时长和质量有所下降，对总体健康产生了不良影响。最近一项针对1508名美国成年人的代表性调查显示，90%的美国人每周至少有几个晚上在睡前1小时内使用某种电子设备。来自世界各国越来越多的证据表明，此类技术使用对睡眠有负面影响。鉴于实验表明，暴露于人造光下会产生提神效果、抑制褪黑素并使生物钟相位偏移，这种对睡眠的负面影响可能是由于这些电子设备发出的富含短波长的光所致。一些报告表明，这些设备会抑制褪黑素水平，但对于其对昼夜节律相位或随后睡眠阶段的影响却知之甚少，这暴露出我们在了解这种日益普及的技术如何影响睡眠方面存在很大差距。在此，我们比较了睡前数小时内在发光设备（LE电子书）上阅读电子书与阅读纸质书的生物学效应。与阅读纸质书相比，阅读LE电子书的参与者入睡时间更长，夜间困倦感减轻，褪黑素分泌减少，生物钟时间推迟，且次日早晨的警觉性降低。这些结果表明，夜间接触LE电子书会使生物钟相位延迟，急性抑制褪黑素，对于理解此类技术对睡眠、表现、健康和安全的影响具有重要意义。
