Psychology Department, Virginia Commonwealth University, 800 W Franklin St, Room 203, PO Box 842018, Richmond, VA 23284-2018.
Psychology Department, Virginia Commonwealth University, 806 W Franklin St, PO Box 842018, Richmond, VA 23284-2018.
Sleep Health. 2019 Feb;5(1):31-48. doi: 10.1016/j.sleh.2018.09.006. Epub 2018 Oct 15.
Light is considered the dominant environmental cue, or zeitgeber, influencing the sleep-wake cycle. Despite recognizing the importance of light for our well-being, less is known about the specific conditions under which light is optimally associated with better sleep. Therefore, a systematic review was conducted to examine the association between the amount and timing of light exposure in relation to sleep outcomes in healthy, community-dwelling adults. A systematic search was conducted of four databases from database inception to June 2016. In total, 45 studies met the review eligibility criteria with generally high study quality excepting for the specification of eligibility criteria and the justification of sample size. The majority of studies involved experimental manipulation of light (n = 32) vs observational designs (n = 13). Broad trends emerged suggesting that (1) bright light (>1000 lux) has positive implications for objectively assessed sleep outcomes compared to dim (<100 lux) and moderate light (100-1000 lux) and (2) bright light (>1000 lux) has positive implications for subjectively assessed sleep outcomes compared to moderate light (100-1000 lux). Effects due to the amount of light are moderated by the timing of light exposure such that, for objectively assessed sleep outcomes, brighter morning and evening light exposure are consistent with a shift in the timing of the sleep period to earlier and later in the day, respectively. For subjectively assessed sleep outcomes, brighter light delivered in the morning was associated with self-reported sleep improvements and brighter evening light exposure was associated with worse self-reported sleep.
光被认为是影响睡眠-觉醒周期的主要环境线索，又称 Zeitgeber。尽管人们认识到光对我们健康的重要性，但对于光与更好睡眠之间的最佳关联的具体条件知之甚少。因此，进行了一项系统综述，以检查健康的、社区居住的成年人的光照量和时间与睡眠结果之间的关系。从数据库建立之初到 2016 年 6 月，对四个数据库进行了系统搜索。共有 45 项研究符合审查标准，除了资格标准的具体规定和样本量的合理性外，这些研究通常具有较高的研究质量。大多数研究涉及光的实验性操作（n=32）与观察性设计（n=13）。出现了一些广泛的趋势，表明（1）与暗（<100 lux）和中光（100-1000 lux）相比，强光（>1000 lux）对客观评估的睡眠结果有积极影响，（2）与中光（100-1000 lux）相比，强光（>1000 lux）对主观评估的睡眠结果有积极影响。光量的影响受到光暴露时间的调节，因此，对于客观评估的睡眠结果，早晨和傍晚更强的光照暴露与睡眠周期的时间分别提前和推迟到白天的时间变化一致。对于主观评估的睡眠结果，早晨更强的光照与自我报告的睡眠改善有关，而傍晚更强的光照与自我报告的睡眠质量下降有关。
