title: Circadian urinary 6-sulphatoxymelatonin, cortisol excretion and locomotor activity in airline pilots during transmeridian flights.
abstract: Airline pilots divided into two groups of age (over and under 50 years) were studied before, during and after westbound (Madrid-Mexico City-Madrid, n = 12) and eastbound (Madrid-Tokyo-Madrid, n = 21) flights. A group of 10 age-matched people staying in Madrid were submitted to the same tests and served as a control group. Changes in urinary 6-sulphatoxymelatonin (6-aMTs) and free cortisol excretion (determined in 6-hr intervals) were measured by radioimmunoassay. Using wrist actigraphy, the circadian locomotor activity rhythm (LAR) was also monitored. Maximal baseline excretion of 6-aMTs occurred between 00:00 and 12:00 hr and maximal excretion of cortisol took place between 6:00 and 12:00 hr in the control group. Analysed globally, older pilots exhibited significantly lower values of 6-aMTs than younger ones. In both flight directions, pilots maintained the pattern of excretion of 6-aMTs, corresponding to baseline. The return flight to Madrid from Mexico and Tokyo coincided with a maximum in 6-aMTs excretion. Pilots kept the cortisol pattern found in the control group, with those over 50 years of age exhibiting significantly lower cortisol values than the younger ones. A 7-hr delay in acrophase of LAR after 2 days in Mexico City was found after cosinor analysis, and similar pre-flight values were found after returning to Madrid. An 8-9-hr acrophase advance of LAR was observed after arriving in Tokyo, with acrophase on the post-return flight day still being advanced 3 4 hr as compared to pre-flight values. Decreases in the amplitude of LAR in older pilots were found at Mexico City, as well as at Tokyo stopover and on post-flight day. Data confirm the occurrence of internal desynchronization in airline crewmembers after transmeridian flights.
authors.affiliation: Department of Physiology, School of Medicine, Complutense University, Madrid, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Tresguerres
authors.forename: C
authors.initials: C
authors.lastname: Ariznavarreta
authors.forename: B
authors.initials: B
authors.lastname: Granados
authors.forename: M
authors.initials: M
authors.lastname: Martín
authors.forename: M A
authors.initials: MA
authors.lastname: Villanúa
authors.forename: D A
authors.initials: DA
authors.lastname: Golombek
authors.forename: D P
authors.initials: DP
authors.lastname: Cardinali
mesh_terms: D000328:Adult; D000401:Aircraft; D002940:Circadian Rhythm / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000652:urine*; D020179:Jet Lag Syndrome / Q000503:physiopathology* / Q000652:urine*; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine*; D008800:Mexico; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009784:Occupational Diseases / Q000503:physiopathology* / Q000652:urine*; D013030:Spain; D014041:Tokyo; D014195:Travel
chemical_list: C054513:6-sulfatoxymelatonin; D008550:Melatonin; D006854:Hydrocortisone