Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA.
Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, MA.
Sleep. 2021 Feb 12;44(2). doi: 10.1093/sleep/zsaa214.
Artificial lighting is omnipresent in contemporary society with disruptive consequences for human sleep and circadian rhythms because of overexposure to light, particularly in the evening/night hours. Recent evidence shows large individual variations in circadian photosensitivity, such as melatonin suppression, due to artificial light exposure. Despite the emerging body of research indicating that the effects of light on sleep and circadian rhythms vary dramatically across individuals, recommendations for appropriate light exposure in real-life settings rarely consider such individual effects. This review addresses recently identified links among individual traits, for example, age, sex, chronotype, genetic haplotypes, and the effects of evening/night light on sleep and circadian hallmarks, based on human laboratory and field studies. Target biological mechanisms for individual differences in light sensitivity include differences occurring within the retina and downstream, such as the central circadian clock. This review also highlights that there are wide gaps of uncertainty, despite the growing awareness that individual differences shape the effects of evening/night light on sleep and circadian physiology. These include (1) why do certain individual traits differentially affect the influence of light on sleep and circadian rhythms; (2) what is the translational value of individual differences in light sensitivity in populations typically exposed to light at night, such as night shift workers; and (3) what is the magnitude of individual differences in light sensitivity in population-based studies? Collectively, the current findings provide strong support for considering individual differences when defining optimal lighting specifications, thus allowing for personalized lighting solutions that promote quality of life and health.
人工照明在当代社会无处不在，由于过度暴露在光线下，尤其是在晚上/夜间，对人类的睡眠和昼夜节律产生了破坏性的影响。最近的证据表明，由于人工光照，昼夜节律对光的敏感性存在很大的个体差异，例如褪黑素的抑制。尽管越来越多的研究表明，光对睡眠和昼夜节律的影响在个体之间有很大的差异，但在现实生活环境中，关于适当光照暴露的建议很少考虑到这些个体差异。
这篇综述根据人类实验室和现场研究，讨论了个体特征（例如年龄、性别、生物钟类型、遗传单倍型）与夜间/夜间光照对睡眠和昼夜节律特征的影响之间最近确定的联系。光敏感性个体差异的潜在生物学机制包括视网膜内和下游（如中央昼夜节律钟）发生的差异。
这篇综述还强调，尽管人们越来越意识到个体差异塑造了夜间/夜间光照对睡眠和昼夜生理的影响，但仍存在广泛的不确定性。这些问题包括：（1）为什么某些个体特征会对光对睡眠和昼夜节律的影响产生不同的影响；（2）在通常夜间暴露于光线下的人群（如夜班工人）中，光敏感性个体差异的转化价值是什么；（3）基于人群的研究中光敏感性个体差异的幅度是多少？
总的来说，这些发现有力地支持了在定义最佳照明规范时考虑个体差异，从而为促进生活质量和健康的个性化照明解决方案提供了依据。
