title: Activity and sleeping time monitored by an accelerometer in rotating shift workers.
abstract: BACKGROUND
  The relationship between total sleep time and activity levels during work before or after sleep in two rotating work shifts was compared.
  
  
  METHODS
  Monitoring of activity levels using an activity-detecting device in the wrist was conducted in 17 rotating shift workers, who ranged in age from 34 to 55 years. The work shifts, consisting of a morning shift (6:30 to 15:15 hours) and an evening shift (15:15 to 24:00 hours), were rotated on a weekly basis. Partial correlation coefficient was calculated after controlling for age.
  
  
  RESULTS
  The total sleep time after the morning shift was significantly related to the activity count before sleep (r=-0.42) or after sleep (r=-0.36). There was also a significant relationship between total sleep time after the evening shift and the activity count before sleep (r=-0.39) or after sleep (r=-0.32). The mean total sleep time of the subjects for the morning shift was 349 minutes, which was significantly lower than that after the evening shift (382 minutes). In addition, the activity count during the morning shift was significantly higher than that during the evening shift.
  
  
  CONCLUSIONS
  The negative relationship between sleep time and activity before or after sleep became clear in shift workers.
authors.affiliation: Department of Hygiene and Public Health, Nippon Medical School, Tokyo, Japan. kawada@nms.ac.jp
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kawada
authors.forename: Takako
authors.initials: T
authors.lastname: Shimizu
authors.forename: Atsunaru
authors.initials: A
authors.lastname: Fujii
authors.forename: Yushiro
authors.initials: Y
authors.lastname: Kuratomi
authors.forename: Sachiko
authors.initials: S
authors.lastname: Suto
authors.forename: Tomoe
authors.initials: T
authors.lastname: Kanai
authors.forename: Akemi
authors.initials: A
authors.lastname: Nishime
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sato
authors.forename: Yasue
authors.initials: Y
authors.lastname: Otsuka
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D002940:Circadian Rhythm; D006801:Humans; D007564:Japan; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D012890:Sleep; D014940:Work Schedule Tolerance