Morning Melatonin Has Limited Benefit as a Soporific for Daytime Sleep After Night Work

Details

• Personal Author:
  Crowley SJ ; Eastman CI ; Fogg LF ; Lee C ; Smith MR
• Description:
  Exogenous melatonin administration in humans is known to exert both chronobiotic (phase shifting) and soporific effects. In a previous study in our lab, young, healthy, subjects worked five consecutive simulated night shifts (23:00 to 07:00 h) and slept during the day (08:30 to 15:30 h). Large phase delays of various magnitudes were produced by the study interventions, which included bright light exposure during the night shifts, as assessed by the dim light melatonin onset (DLMO) before (baseline) and after (final) the five night shifts. Subjects also ingested either 1.8 mg sustained-release melatonin or placebo before daytime sleep. Although melatonin at this time should delay the circadian clock, this previous study found that it did not increase the magnitude of phase delays. To determine whether melatonin had a soporific effect, we controlled the various magnitudes of phase delay produced by the other study interventions. Melatonin (n=18) and placebo (n=18) groups were formed by matching a melatonin participant with a placebo participant that had a similar baseline and final DLMO (+/-1 h). Sleep log measurements of total sleep time (TST) and actigraphic measurements of sleep latency, TST, and three movement indices for the two groups were examined. Although melatonin was associated with small improvements in sleep quality and quantity, the differences were not statistically significant by analysis of variance. However, binomial analysis indicated that melatonin participants were more likely to sleep better than their placebo counterparts on some days with some measures. It was concluded that, the soporific effect of melatonin is small when administered prior to 7 h daytime sleep periods following night shift work. [Description provided by NIOSH]
• Subjects:
  Circadian Rhythm Demography Laboratories Lighting Men Occupational Health Safety Sex Characteristics Shift Work Schedule Sleep Sleep Initiation And Maintenance Disorders Women

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• Keywords:
  Circadian-rhythms Demographic-characteristics Humans Laboratory-testing Sex-factors Shift-work Shift-workers Sleep-deprivation Sleep-disorders Workers
• ISSN:
  0742-0528
• 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
• Volume:
  22
• Issue:
  5
• NIOSHTIC Number:
  nn:20029203
• Citation:
  Chronobiol Int 2005 Sep-Oct; 22(5):873-888
• 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:
  Chronobiology International
• End Date:
  20090430
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1f26facb97b6f950ba342fd3edd9cf6b7fe48e541c33ee05a7a5844f7189308a98c2050f2e9847f9038c9c2238bfcec74a9023d1befc15561d6a3588ce044a2e
• Download URL:
  https://stacks.cdc.gov/view/cdc/190240/cdc_190240_DS1.pdf
• File Type:
  [PDF - 375.77 KB ]