Hypothalamic‐pituitary‐adrenal axis differentially responses to morning and evening psychological stress in healthy subjects

Abstract

Aim The hypothalamic‐pituitary‐adrenal (HPA) axis responds to changing environmental demands including psychological stressors. The aim of the present study was to assess whether the time of day effects on the acute response of HPA axis activity to acute psychological stress. Method We studied 27 healthy young subjects. The subjects were participated two experiments as follows. In the first experiment, subjects were instructed to keep their regular sleep schedule for 2 weeks which were measured by using a wrist‐worn activity monitor. Afterward, to evaluate a diurnal rhythm of salivary cortisol, eight saliva samples were collected during waking period every 2 hours from when the subjects woke up. In the second experiment, the subjects were randomly assigned to two groups. The Trier Social Stress Test (TSST) was performed either in the morning (n = 14) or in the evening (n = 13). We measured diurnal rhythm of salivary cortisol and stress response of salivary cortisol and heart rate by the TSST. Morning and evening tests were started at 2 hours and 10 hours after woke up, respectively. Results All subjects showed a normal diurnal rhythm of salivary cortisol concentration, with a peak in the morning immediately after awaking and a minimum in the evening. The salivary cortisol response after the TSST was significantly increased from the prestress level in the morning but not in the evening. Conclusion The HPA response to acute psychological stress was more pronounced in the morning than in the evening, correlating with the circadian regulation of cortisol synthesis.

Sex differences in stress and immune responses during confinement in Antarctica

“…Furthermore, diurnal cortisol profile, cortisol awaking response and total cortisol excretion over the day are associated with each individual's chronotype classifying, one as rather a morning or evening type [32][33][34]. Additionally, recent studies observed that the hypothalamic-pituitary-adrenal (HPA) response to acute psychological and to high-intensity exercise stress is more pronounced in the morning than in the evening, correlating with the circadian rhythm of cortisol synthesis [35,36]. This finding is in line with our observations of a maintained circadian cortisol rhythm despite higher morning concentrations in women.…”

Fathers' Heightened Stress Responses to Recounting their NICU Experiences Months after Discharge: A Mixed Methods Pilot Study

“…It is well known that cortisol levels are highest on awakening and decrease throughout the day. [51][52][53] For example, Laudat et al 50 showed an average cortisol level of 0.56 versus 0.14 µg/dL between 8:00 A.M. and 8:00 P.M. in healthy adults. To our knowledge, only one study in a similar cohort of parents observed comparable cortisol findings to those in our current study.…”

Night-Time Shift Work and Related Stress Responses: A Study on Security Guards

“…It is known that, under physiological conditions, cortisol is released according to a circadian rhythm characterized by the lowest level at the night, the maximum level in the early morning in response to events such as waking up, and a progressive decrease reaching the minimum value by the end of the day [49,50].…”

“…The factors involved in these responses may be different. In addition to sleep deprivation, it is believed that the particular psychophysical commitment required by the activity conducted on the road plays a fundamental role [49][50][51][52][53][54]. Previous research indicated that exposure to shift work during one's occupational career causes disruption of the circadian time.…”