Crowley Stephanie J, Lee Clara, Tseng Christine Y, Fogg Louis F, Eastman Charmane I
Biological Rhythms Research Laboratory, Rush University Medical Center, Chicago, IL 60612, USA.
J Biol Rhythms. 2003 Dec;18(6):513-23. doi: 10.1177/0748730403258422.
Various combinations of interventions were used to phase-delay circadian rhythms to correct their misalignment with night work and day sleep. Young participants (median age = 22, n = 67) participated in 5 consecutive simulated night shifts (2300 to 0700) and then slept at home (0830 to 1530) in darkened bedrooms. Participants wore sunglasses with normal or dark lenses (transmission 15% or 2%) when outside during the day. Participants took placebo or melatonin (1.8 mg sustained release) before daytime sleep. During the night shifts, participants were exposed to a moving (delaying) pattern of intermittent bright light (approximately 5000 lux, 20 min on, 40 min off, 4-5 light pulses/night) or remained in dim light (approximately 150 lux). There were 6 intervention groups ranging from the least complex (normal sunglasses) to the most complex (dark sunglasses + bright light + melatonin). The dim light melatonin onset (DLMO) was assessed before and after the night shifts (baseline and final), and 7 h was added to estimate the temperature minimum (Tmin). Participants were categorized by their amount of reentrainment based on their final Tmin: not re-entrained (Tmin before the daytime dark/sleep period), partially re-entrained (Tmin during the first half of dark/sleep), or completely re-entrained (Tmin during the second half of dark/ sleep). The sample was split into earlier participants (baseline Tmin < or = 0700, sunlight during the commute home fell after the Tmin) and later participants (baseline Tmin > 0700). The later participants were completely re-entrained regardless of intervention group, whereas the degree of re-entrainment for the earlier participants depended on the interventions. With bright light during the night shift, almost all of the earlier participants achieved complete re-entrainment, and the phase delay shift was so large that darker sunglasses and melatonin could not increase its magnitude. With only room light during the night shift, darker sunglasses helped earlier participants phase-delay more than normal sunglasses, but melatonin did not increase the phase delay. The authors recommend the combination of intermittent bright light during the night shift, sunglasses (as dark as possible) during the commute home, and a regular, early daytime dark/sleep period if the goal is complete circadian adaptation to night-shift work.
研究采用了各种不同的干预组合来延迟昼夜节律，以纠正其与夜班和白天睡眠的不同步。年轻参与者（年龄中位数 = 22岁，n = 67）连续参加了5次模拟夜班（23:00至07:00），然后在家（08:30至15:30）在黑暗的卧室中睡觉。参与者在白天外出时佩戴普通或深色镜片的太阳镜（透光率分别为15%或2%）。参与者在白天睡眠前服用安慰剂或褪黑素（1.8毫克缓释片）。在夜班期间，参与者暴露于移动（延迟）模式的间歇性强光（约5000勒克斯，开20分钟，关40分钟，每晚4 - 5个光脉冲）下，或一直处于昏暗灯光（约150勒克斯）中。共有6个干预组，从最不复杂（普通太阳镜）到最复杂（深色太阳镜 + 强光 + 褪黑素）。在夜班前后（基线和最终）评估暗光褪黑素起始时间（DLMO），并加上7小时以估计体温最低点（Tmin）。根据最终的Tmin对参与者的重新调整程度进行分类：未重新调整（白天黑暗/睡眠期之前的Tmin）、部分重新调整（黑暗/睡眠期前半段的Tmin）或完全重新调整（黑暗/睡眠期后半段的Tmin）。样本被分为较早的参与者（基线Tmin≤07:00，回家通勤途中的阳光在Tmin之后）和较晚的参与者（基线Tmin > 07:00）。较晚的参与者无论干预组如何都能完全重新调整，而较早参与者的重新调整程度则取决于干预措施。夜班期间有强光时，几乎所有较早的参与者都实现了完全重新调整，且相位延迟偏移非常大，以至于更深色的太阳镜和褪黑素都无法增加其幅度。夜班期间只有室内灯光时，较深色的太阳镜比普通太阳镜更有助于较早的参与者延迟相位，但褪黑素并未增加相位延迟。作者建议，如果目标是使昼夜节律完全适应夜班工作，可采用夜班期间间歇性强光、回家通勤途中佩戴尽可能深色的太阳镜以及规律、较早的白天黑暗/睡眠期相结合的方法。
