Light-Induced Changes of the Circadian Clock of Humans: Increasing Duration is More Effective than Increasing Light Intensity
Light-Induced Changes of the Circadian Clock of Humans: Increasing Duration is More Effective than Increasing Light Intensity
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DOI：
10.1093/sleep/34.5.593
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发表时间：
2011-06-01
期刊：
影响因子：
5.6
通讯作者：
Zee, Phyllis C.
中科院分区：
文献类型：
--
作者：
Dewan, Karuna;Benloucif, Susan;Zee, Phyllis C.
研究目的：评价增加暴露强度和(或)持续时间对光诱导的人体生物钟计时变化的影响。设计：多因素随机对照试验，受试者之间和受试者内设计地点：一家学术医学中心的Geberak临床研究中心(GCRC)。参与者：56名健康的年轻受试者(20-40岁)干预：研究受试者接受2次独立的4晚/3天的强光或暗光治疗(随机顺序)，治疗时间已知会导致昼夜节律的相位延迟。强光的强度和持续时间通过随机分配到9种处理条件中的一种(在2000、4000或8000lux下持续1、2或3小时)来确定。测量和结果：在9种条件下，处理诱导的暗光褪黑素起始(DLMO)和暗光褪黑素偏移量(DLMOff)的变化是光诱导的昼夜褪黑素节律时间变化的方差(ANOVA)，结果表明，将光照持续时间从1改变到3小时增加了光诱导延迟的幅度。相反，从中等强度光(2000lux)增加到高强度光(8000lux)并没有改变褪黑激素昼夜节律的相位延迟的幅度。结论：本研究结果表明，对于人类昼夜节律睡眠障碍的光疗，较长时间的中等强度光可能比较短的高强度光暴露时间更有效。
Study Objectives: To evaluate the effect of increasing the intensity and/or duration of exposure on light-induced changes in the timing of the circadian clock of humans.Design: Multifactorial randomized controlled trial, between and within subject designSetting: Geberak Clinical Research Center (GCRC) of an academic medical centerParticipants: 56 healthy young subjects (20-40 years of age)Interventions: Research subjects were admitted for 2 independent stays of 4 nights/3 days for treatment with bright or dim-light (randomized order) at a time known to induce phase delays in circadian timing. The intensity and duration of the bright light were determined by random assignment to one of the 9 treatment conditions (duration of 1, 2, or 3 hours at 2000, 4000, or 8000 lux).Measurements and Results: Treatment-induced changes in the dim light melatonin onset (DLMO) and dim light melatonin offset (DLMOff) were variance (ANOVA) of light-induced changes in the time of the circadian melatonin rhythm for the 9 conditions revealed that changing the duration of the loight exposure from 1 to 3 h increased the magnitude of light-induced delays. In contrast, increasing from moderate (2,000 lux) to high (8,000 lux) intensity light did not alter the magnitude of phase delays of the circadian melatonin rhythm.Conclusions: Results from the present study suggest that for phototherapy of circadian rhythm sleep disorders in humans, a longer period of moderate intensity light may be more effective than a shorter exposure period of high intensity light.