title: Changes in the concentration of urinary 6-sulphatoxymelatonin during a week of simulated night work.
abstract: The aim of the study was to examine the adaptation of participants to a common night work schedule using urinary 6-sulphatoxymelatonin (aMT6s) concentration as the circadian phase marker. Fifteen adults (7 male, 8 female, age = 21.9 yr) spent nine consecutive nights in the laboratory, including: (i) adaptation sleep, (ii) baseline sleep, and (iii) seven simulated night shifts (23:00-07:00 h) followed by daytime sleep. During the baseline and daytime sleeps, participants collected urine samples which were subsequently assayed for aMT6s. The concentration of aMT6s in urine for the first three day sleeps was significantly lower than for the baseline sleep, but there was no difference in aMT6s concentrations between any of the last three day sleeps and the baseline sleep. The data indicate that people may adapt to a pattern of work that includes seven consecutive night shifts if they adhere to a fixed sleep schedule, if their exposure to morning sunlight is minimised, and if they are provided with an ideal sleep environment.
authors.affiliation: Centre for Sleep Research, University of South Australia, Level 5 Basil Hetzel Institute TQEH 28 Woodville Road, Woodville, South Australia 5011, Australia.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Roach
authors.forename: Nicole
authors.initials: N
authors.lastname: Lamond
authors.forename: Jill
authors.initials: J
authors.lastname: Dorrian
authors.forename: Helen
authors.initials: H
authors.lastname: Burgess
authors.forename: Alexandra
authors.initials: A
authors.lastname: Holmes
authors.forename: Adam
authors.initials: A
authors.lastname: Fletcher
authors.forename: Kirsty
authors.initials: K
authors.lastname: McCulloch
authors.forename: Drew
authors.initials: D
authors.lastname: Dawson
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine*; D010561:Personnel Staffing and Scheduling; D012890:Sleep / Q000502:physiology*; D020178:Sleep Disorders, Circadian Rhythm / Q000652:urine*; D013995:Time; D014940:Work Schedule Tolerance / Q000502:physiology*
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin