title: Shift type and season affect adaptation of the 6-sulphatoxymelatonin rhythm in offshore oil rig workers.
abstract: Previously we have shown that the 6-sulphatoxymelatonin rhythm of oil rig workers on a 2-week night shift (1800-0600 h) adapts to the shift via a phase delay. We now report the findings of a study on two offshore drill crews working a 1 week day (1200-0000 h), 1 week night (0000-1200 h) swing shift. Urine samples were collected every 2-3 h throughout the subjective days, with over-sleep collections, for the measurement of 6-sulphatoxymelatonin by radioimmunoassay. One crew (n = 11), studied in November, showed no change in their 6-sulphatoxymelatonin rhythm during night shift. The other crew (n = 7), studied in March, showed a significant phase advance of the rhythm during night shift. The data indicate that both the type of shift and the season influence the direction and degree of adaptation.
authors.affiliation: Endocrinology and Metabolism Group, School of Biological Sciences, University of Surrey, Guildford, UK.
authors.forename: R G
authors.initials: RG
authors.lastname: Barnes
authors.forename: M J
authors.initials: MJ
authors.lastname: Forbes
authors.forename: J
authors.initials: J
authors.lastname: Arendt
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D008550:Melatonin / Q000031:analogs & derivatives* / Q000502:physiology / Q000652:urine; D008875:Middle Aged; D016272:Occupational Health; D010578:Petroleum; D011863:Radioimmunoassay; D012621:Seasons; D012890:Sleep / Q000502:physiology; D014940:Work Schedule Tolerance
chemical_list: D010578:Petroleum; C054513:6-sulfatoxymelatonin; D008550:Melatonin