Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY.
Office of Federal High-Performance Green Buildings, US General Services Administration.
Sleep Health. 2017 Jun;3(3):204-215. doi: 10.1016/j.sleh.2017.03.005. Epub 2017 Apr 23.
By affecting the internal timing mechanisms of the brain, light regulates human physiology and behavior, perhaps most notably the sleep-wake cycle. Humans spend over 90% of their waking hours indoors, yet light in the built environment is not designed to affect circadian rhythms.
Using a device calibrated to measure light that is effective for the circadian system (circadian-effective light), collect personal light exposures in office workers and relate them to their sleep and mood.
The research was conducted in 5 buildings managed by the US General Services Administration.
This study recruited 109 participants (69 females), of whom 81 (54 females) participated in both winter and summer.
Self-reported measures of mood and sleep, and objective measures of circadian-effective light and activity rhythms were collected for 7 consecutive days.
Compared to office workers receiving low levels of circadian-effective light in the morning, receiving high levels in the morning is associated with reduced sleep onset latency (especially in winter), increased phasor magnitudes (a measure of circadian entrainment), and increased sleep quality. High levels of circadian-effective light during the entire day are also associated with increased phasor magnitudes, reduced depression, and increased sleep quality.
The present study is the first to measure personal light exposures in office workers using a calibrated device that measures circadian-effective light and relate those light measures to mood, stress, and sleep. The study's results underscore the importance of daytime light exposures for sleep health.
光通过影响大脑的内部定时机制来调节人体的生理和行为，对睡眠-觉醒周期的影响尤为显著。人类超过 90%的清醒时间都在室内度过，但建筑环境中的光并不是为了影响昼夜节律而设计的。
使用经过校准的、可测量对昼夜节律系统有效的光（昼夜节律有效光）来测量上班族的个人光照暴露情况，并将其与他们的睡眠和情绪联系起来。
该研究在由美国总务管理局管理的 5 座建筑中进行。
这项研究招募了 109 名参与者（69 名女性），其中 81 名（54 名女性）参与了冬季和夏季的研究。
连续 7 天收集了自我报告的情绪和睡眠测量数据，以及昼夜节律有效光和活动节律的客观测量数据。
与早晨接收到低水平昼夜节律有效光的上班族相比，早晨接收到高水平昼夜节律有效光与入睡潜伏期缩短（尤其是在冬季）、相幅幅度增加（衡量昼夜节律同步的指标）和睡眠质量提高有关。全天接收到高水平的昼夜节律有效光也与相幅幅度增加、抑郁减少和睡眠质量提高有关。
本研究首次使用经过校准的、可测量昼夜节律有效光的设备来测量上班族的个人光照暴露情况，并将这些光照测量值与情绪、压力和睡眠联系起来。该研究结果强调了白天光照暴露对睡眠健康的重要性。
