title: Resynchronization of hormonal rhythms after an eastbound flight in humans: effects of slow-release caffeine and melatonin.
abstract: The aim of this work was to investigate the potential chronobiotic properties of slow-release caffeine, in comparison with melatonin, on resynchronization of endogenous melatonin and cortisol secretions after an eastbound flight by jet incurring a time loss of 7 h. A group of 27 reservists of the US Air Force received either slow-release caffeine (300 mg), melatonin (5 mg) or placebo before, during and/or after the transmeridian flight. Saliva and urine were sampled before the flight in the United States (from day -2 to day 0) and after the flight in France (from day 1 to day 10). Saliva was collected once a day on waking to determine saliva melatonin and cortisol concentrations. In addition, concentrations of caffeine in saliva were determined three times a day and of 6-sulphatoxymelatonin in urine collected overnight to check that the treatment regimes had been complied with. From day 3 to day 5, post-flight saliva melatonin concentrations were significantly different from control values in the placebo group only. During treatment with melatonin, the mean urinary 6-sulphatoxymelatonin concentration in the melatonin group was more than twice as high as in the two other groups. In the slow-release caffeine group and the melatonin group, mean saliva cortisol concentrations were significantly lower than control from day 2 to day 5, whereas the placebo group had a mean saliva cortisol concentration significantly lower than the control value from day 2 to day 9. In conclusion, these results indicate that administration of slow-release caffeine, as well as of melatonin, allows a faster resynchronization of hormone rhythms during the 4 days following an eastbound flight incurring the loss of 7 h.
authors.affiliation: Département de Physiologie, Institut de Médecine Aérospatiale du Service de Santé des Armées, Brétigny-sur-Orge, France. cpierard@imassa.fr
authors.forename: C
authors.initials: C
authors.lastname: Piérard
authors.forename: M
authors.initials: M
authors.lastname: Beaumont
authors.forename: M
authors.initials: M
authors.lastname: Enslen
authors.forename: F
authors.initials: F
authors.lastname: Chauffard
authors.forename: D X
authors.initials: DX
authors.lastname: Tan
authors.forename: R J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: A
authors.initials: A
authors.lastname: Fontan
authors.forename: J
authors.initials: J
authors.lastname: French
authors.forename: O
authors.initials: O
authors.lastname: Coste
authors.forename: D
authors.initials: D
authors.lastname: Lagarde
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000097:blood; D000328:Adult; D002110:Caffeine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000697:Central Nervous System Stimulants / Q000008:administration & dosage* / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism; D020179:Jet Lag Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism / Q000652:urine; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry
chemical_list: D000276:Adjuvants, Immunologic; D000697:Central Nervous System Stimulants; D003692:Delayed-Action Preparations; C054513:6-sulfatoxymelatonin; D002110:Caffeine; D008550:Melatonin; D006854:Hydrocortisone