Related Experiment Video
Updated: Jul 20, 2025
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Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
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Circadian misalignment increases 24-hour acylated ghrelin in chronic shift workers: a randomized crossover trial
Jingyi Qian1,2, Christopher J Morris1,2, Rosanna Caputo1,3
1Medical Chronobiology Program, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Obesity (Silver Spring, Md.)
|August 4, 2023
Summary
Circadian misalignment in chronic shift workers increases hunger hormone levels and feelings of hunger. This disruption in the body
Area of Science:
- Chronobiology
- Metabolic Health
- Occupational Health
Background:
- Shift work is associated with circadian misalignment and increased obesity risk.
- Previous studies in non-shift workers suggest circadian misalignment disrupts energy balance.
- The impact of circadian misalignment in chronic shift workers remains under-investigated.
Purpose of the Study:
- To examine the effects of circadian misalignment on energy balance regulation in chronic shift workers.
- To investigate hormonal and subjective appetite responses to circadian misalignment.
Main Methods:
- A randomized crossover study involving seven healthy chronic night shift workers.
- Two 3-day laboratory protocols: night work (circadian misalignment) and day work (circadian alignment).
- Controlled dietary intake and measured hormonal levels, appetite, energy expenditure, and activity.
Main Results:
- Circadian misalignment significantly increased 24-hour acylated ghrelin levels by ~17% (p=0.009).
- Hunger at breakfast increased by ~14% during circadian misalignment (p=0.04).
- No significant changes in energy expenditure or respiratory exchange ratio were observed.
- Unexpectedly, 24-hour behavioral activity increased by ~38% (p<0.0001) despite increased sleepiness.
Conclusions:
- Circadian misalignment acutely increases acylated ghrelin and hunger in chronic shift workers, independent of diet.
- These findings suggest a potential mechanism linking circadian misalignment to obesity in shift workers.
- Further research is needed to determine the long-term contribution of these effects to obesity risk.
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