Altered coordination between sleep timing and cortisol profiles in night working female hospital employees

May 9, 2024Psychoneuroendocrinology

Changes in the relationship between sleep patterns and stress hormone levels in female hospital workers who work at night

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Cortisol levels in female hospital employees on night shifts were found to be lower at night when higher levels are typically needed for work activities.

Shift workers exhibited a flattened U-shaped cortisol profile after waking, contrasting with the steep negative slope seen in non-shift workers during the day.
Mean cortisol levels in night shift workers were significantly lower 42 to 56 minutes and 1.8 to 11.9 hours after waking compared to day shifts.
Cortisol levels were higher 14.9 to 22 hours after waking in night shift workers, when levels should normally be low.
These findings suggest a misalignment in cortisol rhythms due to shift work, particularly affecting nighttime cortisol levels.

AI simplified

BACKGROUND: Cortisol typically peaks in the morning after waking up and declines throughout the day, reaching its lowest levels during nighttime sleep. Shift work can cause misalignment between cortisol levels and sleep-wake timing. We analyzed this misalignment in female shift workers focusing on the timing and extent of these changes.

METHODS: We conducted a cross-sectional study involving 68 shift workers (aged 37 ± 10 years) and 21 non-shift workers (aged 45 ± 10 years) from a hospital. Shift workers were monitored through two day shifts and three night shifts, whereas non-shift workers were monitored during two day shifts. Each participant collected six to eight saliva samples (depending on their shift type) and provided sleep timing information, which was recorded via polysomnography and sleep diaries. Generalized additive mixed models were used to estimate shift-specific differences in cortisol smooth curves. Summary measures calculated for the cortisol smooth curves included cortisol awakening response, peak-to-bed slope, and total output.

RESULTS: Between shift workers and non-shift workers, we observed similar diurnal cortisol profiles with a steep negative diurnal slope during day shifts. In shift workers on night shifts, a flattened U-shaped cortisol profile after the post-awakening maximum was observed, with a peak-to-bed slope close to zero. When comparing night to day shifts in the group of shift workers, mean cortisol levels were lower between 42 and 56 minutes and 1.8-11.9 hours after waking up, and higher between 14.9 and 22 hours after waking up.

CONCLUSION: Our findings indicate altered cortisol profiles in female hospital employees on night shifts. Specifically, cortisol levels were lower at night when higher levels would typically be necessary for work activities, and higher at bedtime after a night shift, when levels should normally be low.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

Altered coordination between sleep timing and cortisol profiles in night working female hospital employees

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief