Shift Work Schedule
Conditions
Brief summary
In an exploratory observational pilot study, the investigators will focus on the effects of short-term circadian misalignment induced by shift work on multidimensional measurements including glucose excursion, metabolic health, circadian rhythms (measured in vitro and in vivo), sleep/wake cycles and ambient light, eating and activity patterns, well-being and attention.
Interventions
OTHERExposure to shift work
Detailed questionnaire adapted from the Standard Shiftwork Index, measured at inclusion
Sponsors
Tinh-Hai Collet, MD
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
20 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Men and women * Age 20-50 years * Working ≥ 80% full-time equivalent over the previous month and during the study * Working night shifts (i.e. shifts that comprise working hours between 23h and 06h) in rotation with day shifts (i.e. shifts that comprise working hours between 06h and 20h) * Planned to work at least 3 consecutive night shifts during the study preceded by at least a day off or day shift * Planned to work at least 3 consecutive day shifts during the study * Confident use of a smartphone compatible with the study application (iOS, Android) and able to regularly take pictures of consumed food/drinks * Able to give a fully informed consent and follow the study procedures
Exclusion criteria
* Planned or current pregnancy during the study * Menopausal women * Major illness or hospitalization over the previous month * Carries a pacemaker, pump or other medical device that can be disabled by a magnet * Major mental illness * Trip to a different time zone (≥ 2-hour time difference) over the previous month or planned during the study * Enrolled in an interventional clinical trial (potentially interfering with the main outcomes) over the previous month or planned during the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in glucose excursion | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by Continuous Glucose Monitoring |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Difference in nutrient intake | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Total calorie and macronutrient intake over a 24-hour period |
| Difference in sleep quality | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by the Pittsburgh Sleep Quality Index (PSQI), score ranges from 0 to 21 points, 0 indicating no difficulty and 21 severe difficulties |
| Difference in attention and sleepiness | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by the Sustained Attention to Response Test |
| Difference in well-being | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by the World Health Organization-5 questionnaire (WHO-5), score ranges from 0 to 25, 0 indicating worst possible and 25 best possible |
| Difference in mental health outcomes | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by the Patient Health Questionnaire-9 (PHQ-9), score ranges from 0 to 27, 0 indicating no depression and 27 severe depression |
| Difference in fasting glucose | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by clinical chemistry (mmol/L) |
| Difference in weight | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Body weight (Kg) |
| Difference in waist circumference | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Waist circumference (cm) assessed with a measuring tape |
| Difference in lipid profile | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol measured by clinical chemistry (mmol/L) |
| Difference in blood hormonal profile | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Insulin (mIU/L), thyroid-stimulating hormone (mIU/L), cortisol (nmol/L) measured by clinical chemistry |
| Difference in eating duration | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | Time from the first to last caloric intake over a 24-hour period |
| Difference in systolic and diastolic blood pressure | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by blood pressure arm cuff |
| Difference in heart rate variability | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by wearable sensor |
| Difference in physical activity | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by actigraphy and the International Physical Activity Questionnaire |
| Difference in sleep/wake cycles | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by actigraphy |
Other
| Measure | Time frame | Description |
|---|---|---|
| Difference in the exposure to ambient light | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by wearable spectrometer and the light exposure behaviour assessment (LEBA) questionnaire |
| Difference in the core body temperature | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by a wearable skin temperature and heat transfer sensor |
| Difference in blood metabolomic parameters | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by high-throughput mass spectrometry metabolomics, semi-quantitative identification of small metabolites involved in carbohydrate, fat, protein, and steroid metabolism |
| Difference in lipid metabolism | Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months | As measured by high-throughput mass spectrometry lipidomics |
Countries
Switzerland
Outcome results
None listed