Recovery of circadian rhythm of plasma cortisol levels after a 3-day trip between Tokyo and San Francisco.
The objective of the present study is to investigate the change in the circadian rhythm of plasma cortisol levels following a 3-d trip and a westbound return flight from San Francisco (SFO) to Tokyo. Six healthy male students volunteered for the project. Plasma cortisol levels were monitored 4 times daily for 13 d during the experimental period. In Tokyo, the baseline pattern of cortisol concentrations showed the classical diurnal profile. During the 50-h stay in SFO, phase advancement of 8 h was observed for the initial 32 h. This was followed by a disturbance in the profile for the remaining 18-h period. After returning to Tokyo, the subjects exhibited the original diurnal pattern beginning Day 1. However, complete resynchronization was not apparent until Day 4 after the return.
Tajima
N
N
Flight Crew Medical Service Department, Japan Airlines, Tokyo.
Uematsu
M
M
Asukata
I
I
Yamamoto
K
K
Sasaki
M
M
Hokari
M
M
D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D000337:Aerospace Medicine; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D012495:San Francisco; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014041:Tokyo; D014195:Travel; D014851:Wakefulness / Q000502:physiology
D006854:Hydrocortisone