Revell Victoria L, Kim Hyungsoo, Tseng Christine Y, Crowley Stephanie J, Eastman Charmane I
Biological Rhythms Research Lab, Rush University Medical Center, Chicago, IL 60612, USA.
J Pineal Res. 2005 Sep;39(2):195-200. doi: 10.1111/j.1600-079X.2005.00236.x.
The aim of this study was to determine whether circadian phase from salivary melatonin profiles is the same when measured in phase assessments 1 wk apart. Eleven healthy young men and women maintained a fixed, home sleep-wake schedule, in bed, in the dark 23:00-07:00 hr on weekdays. On Friday and Saturday nights they were permitted to wake up and go to bed up to 1 hr later, and on Saturdays and Sundays they could nap between 13:30 and 16:30 hr. The study was run in the summer. Subjects wore sunglasses when outside during the day, and went outside for at least 15 min between 08:00 and 09:00 hr each morning. They maintained this schedule for 15 days before the first assessment and the 6 days in between the two assessments. During the assessments subjects remained awake overnight in <5 lux and gave saliva samples every 30 min. A recovery nap (13:00-17:00 hr) followed the first session. The dim light melatonin onset (DLMO), offset (DLMOff) and midpoint were used as phase markers. There was minimal change in their timing between the two phase assessments. The average absolute change in midpoint (the change in phase regardless of direction) was 20 min. There was a small, 30 min delay in the DLMO. Thus, circadian phase can be measured a week in advance of any phase shifting intervention and, as long as the prescribed sleep and morning light schedule is maintained, the phase at the start of treatment can be confidently estimated.
本研究的目的是确定相隔1周进行的相位评估中，根据唾液褪黑素谱测得的昼夜节律相位是否相同。11名健康的年轻男性和女性维持固定的居家睡眠-清醒时间表，工作日23:00至07:00在床上、在黑暗中休息。周五和周六晚上，他们可以晚睡晚起1小时，周六和周日可以在13:30至16:30之间小睡。研究在夏季进行。受试者白天外出时佩戴太阳镜，每天上午08:00至09:00之间至少外出15分钟。在第一次评估前，他们维持此时间表15天，两次评估之间间隔6天。评估期间，受试者在<5勒克斯的环境中通宵保持清醒，每30分钟采集一次唾液样本。第一次检测后进行恢复性小睡（13:00至17:00）。暗光褪黑素开始（DLMO）、结束（DLMOff）和中点用作相位标记。两次相位评估之间，它们的时间变化极小。中点的平均绝对变化（不考虑方向的相位变化）为20分钟。DLMO有30分钟的小延迟。因此，可以在任何相位转移干预前一周测量昼夜节律相位，并且只要维持规定的睡眠和早晨光照时间表，就可以可靠地估计治疗开始时的相位。
