Circadian Phase Determined from Melatonin Profiles Is Reproducible After 1 Wk in Subjects Who Sleep Later on Weekends

Details

• Personal Author:
  Crowley SJ ; Eastman CI ; Kim H ; Revell VL ; Tseng, Chih-Yu
• Description:
  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. [Description provided by NIOSH]
• Subjects:
  Age Factors Circadian Rhythm Demography Occupational Health Safety Sex Characteristics Sleep Sleep Initiation And Maintenance Disorders
• Keywords:
  Age-factors Circadian-rhythms Demographic-characteristics Sampling Sampling-methods Sex-factors Sleep-deprivation Sleep-disorders
• ISSN:
  0742-3098
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Illinois ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  195-200
• Volume:
  39
• Issue:
  2
• NIOSHTIC Number:
  nn:20028903
• Citation:
  J Pineal Res 2005 Sep; 39(2):195-200
• Contact Point Address:
  Dr Victoria Revell, Biological Rhythms Research Lab, Rush University Medical Center, 1645 W Jackson Blvd, Suite 425, Chicago, IL 60612, USA
• Email:
  victoria_l_revell@rush.edu
• Federal Fiscal Year:
  2005
• NORA Priority Area:
  Work Environment and Workforce: Organization of Work
• Performing Organization:
  Rush University Medical Center, Chicago, Illinois
• Peer Reviewed:
  True
• Start Date:
  19990930
• Source Full Name:
  Journal of Pineal Research
• End Date:
  20090430
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:638d1bd654637b7a1cee38fe99a95d636374481541f74e1918f9c7584fb7a61bf736529c37bf23b6a3c0e5dc5277f5b84c6d8bf09756c07e099f14d56ff480ab
• Download URL:
  https://stacks.cdc.gov/view/cdc/189996/cdc_189996_DS1.pdf
• File Type:
  [PDF - 174.49 KB ]