Shift Work ScheduleOPTI-SHIFTNCT05177965
The Metabolic and Circadian Effects of Shift Work
An observational study of Shift Work Schedule, run by Tinh-Hai Collet, MD at 1 site in Switzerland.
Trial 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… Read more about this study
- Who is it for?
- Ages 20 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Shift Work Schedule
- What is being tested?
- Exposure to shift work
- How many people
- 72 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Feb 2022to 30 Aug 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Shift workers
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Metabolic and Circadian Effects of Shift Work - An Observational Study
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.
- Conditions
- Shift Work Schedule
- Being tested
- Exposure to shift work
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exposure to shift workOther
Detailed questionnaire adapted from the Standard Shiftwork Index, measured at inclusion
| Study group | Role | What they receive |
|---|---|---|
| Shift workers | Measurements repeated during a series of day shifts and during a series of night shifts Receives: Other: Exposure to shift work |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in glucose excursion
As measured by Continuous Glucose Monitoring
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Secondary outcomes (15)
Difference in fasting glucose
As measured by clinical chemistry (mmol/L)
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in weight
Body weight (Kg)
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in waist circumference
Waist circumference (cm) assessed with a measuring tape
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in lipid profile
Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol measured by clinical chemistry (mmol/L)
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in blood hormonal profile
Insulin (mIU/L), thyroid-stimulating hormone (mIU/L), cortisol (nmol/L) measured by clinical chemistry
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in eating duration
Time from the first to last caloric intake over a 24-hour period
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in nutrient intake
Total calorie and macronutrient intake over a 24-hour period
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in systolic and diastolic blood pressure
As measured by blood pressure arm cuff
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in heart rate variability
As measured by wearable sensor
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in physical activity
As measured by actigraphy and the International Physical Activity Questionnaire
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in sleep/wake cycles
As measured by actigraphy
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in sleep quality
As measured by the Pittsburgh Sleep Quality Index (PSQI), score ranges from 0 to 21 points, 0 indicating no difficulty and 21 severe difficulties
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in attention and sleepiness
As measured by the Sustained Attention to Response Test
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in well-being
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
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in mental health outcomes
As measured by the Patient Health Questionnaire-9 (PHQ-9), score ranges from 0 to 27, 0 indicating no depression and 27 severe depression
Measured: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jan 2022
- Study start1 Feb 2022
- Primary completion30 Aug 2024
- Study completion30 Aug 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Shift Work ScheduleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 72 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tinh-Hai Collet, MD
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Tinh-Hai Collet, MD, University Hospital, Geneva
- Investigators
- Tinh-Hai Collet, MD, Principal investigator, Geneva University Hospitals, Geneva
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05177965
- Sponsor's protocol ID
- 2021-01088
- Acronym
- OPTI-SHIFT
- Status last verified
- Nov 2025
- First submitted
- 18 Nov 2021
- Last updated
- 18 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Hartmeyer SL, Phillips NE, Jassil FC, Joris C, Dibner C, Collet TH, Andersen M. Multi-Wearable Approach for Monitoring Diurnal Light Exposure and Body Rhythms in Nightshift Workers. Acta Physiol (Oxf). 2025 Jul;241(7):e70069. doi: 10.1111/apha.70069.
PubMed 40485643
Study at a glance
From the registry record, last updated by the sponsor on 18 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Metabolic and Circadian Effects of Shift Work - An Observational Study
- ClinicalTrials.gov ID
- NCT05177965
- Acronym / sponsor ID
- OPTI-SHIFT / 2021-01088
- Conditions
- Shift Work Schedule
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 72 participants (actual)
- Lead sponsor
- Tinh-Hai Collet, MDUniversity, hospital or other
- Study start
- 1 Feb 2022 (actual)
- Primary completion
- 30 Aug 2024 (actual)
- Study completion
- 30 Aug 2024 (actual)
- First posted
- 5 Jan 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Shift workers | – | Other: Exposure to shift workMeasurements repeated during a series of day shifts and during a series of night shifts |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Shift workers
Key inclusion criteria (8 listed)
- 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
Key exclusion criteria (7 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Exposure to shift workDetailed questionnaire adapted from the Standard Shiftwork Index, measured at inclusion | Other | Shift workers |
Primary outcome
Difference in glucose excursion
Time frame: 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
15 secondary outcomes
Difference in fasting glucose
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in weight
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in waist circumference
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in lipid profile
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in blood hormonal profile
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in eating duration
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in nutrient intake
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in systolic and diastolic blood pressure
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in heart rate variability
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in physical activity
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in sleep/wake cycles
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in sleep quality
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in attention and sleepiness
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in well-being
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Difference in mental health outcomes
Time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Nov 2025.
- Results publication: PubMed 40485643Hartmeyer SL, Phillips NE, Jassil FC, Joris C, Dibner C, Collet TH, Andersen M. Multi-Wearable Approach for Monitoring Diurnal Light Exposure and Body Rhythms in Nightshift Workers. Acta Physiol (Oxf). 2025 Jul;241(7):e70069. doi: 10.1111/apha.70069.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tinh-Hai Collet, MD principal investigator
Geneva University Hospitals, Geneva
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Shift Work Schedule, run by Tinh-Hai Collet, MD at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in glucose excursion (time frame: Between a series of day shifts and a series night shifts, separated by an interval from 10 days to 3 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05177965, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Nov 2025.