Healthy VolonteersNAP-WORKNCT05955729
Effect of a Short Nap During the Night Shift of Healthcare Workers on Endothelial Function
A study testing On-duty Nap, EndoPAT and Popmeter® in people with Healthy Volonteers, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
Trial summary
Night shift work is well known to cause health disruption in short and long term. It has been reported that among healthcare workers, nurses slept less than 6 h/24h. Consequences of such short sleep duration has been associated to long term issues such as endothelial dysfunction associated with cardiovascular… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Volonteers
- What is being tested?
- On-duty Nap, EndoPAT and Popmeter®
- Type of treatment
- Medical device, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteFrance
- Study dates
- 19 Feb 2024to 22 Dec 2025
- Phase
- Interventional
- 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 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Being a paramedical caregiverr (nurse or care assistant) at Saint-Etienne University Hospital
- Be aAged between 18 and 65
- Working at least 80% of a full-time equivalent post
- Working 12-hour shifts (day/night) in continuous care services
- Being affiliated or entitled under a social security scheme
- Havinge received informed information about the study and have co-signed, with the investigator, a consent to participate in the study
Who cannot join
- Have made a tTrans meridian journey in the last month prior to the study
- Have a mMedically diagnosed sleep disorder such asof the hypersomnia or insomnia type
- Have a diagnosed and treated mental pathology
- Usually take a nap in the workplace in a quiet room
- Be pregnant or breastfeeding
- Have medically diagnosed neurovascular or neuromuscular pathologies
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of a Short Nap During the Night Shift of Healthcare Workers on Endothelial Function: NAP-WORK Randomized Controlled Study
Night shift work is well known to cause health disruption in short and long term. It has been reported that among healthcare workers, nurses slept less than 6 h/24h. Consequences of such short sleep duration has been associated to long term issues such as endothelial dysfunction associated with cardiovascular diseases, arterial hypertension and type 2 diabetes. Countermeasures such as nap at work has potential effects on reducing the prevalence of cardiovascular diseases. However, to our knowledge, no studies have objectively investigated the effects of napping on endothelial function in a longitudinal design. Therefore, this study aims to investigate the effect of a 30 minutes on-duty nap during night work for 12 weeks on caregivers endothelial dysfunction.
- Conditions
- Healthy Volonteers
- Being tested
- On-duty Nap, Control condition (30-min rest), EndoPAT, Popmeter®, Panasonic EW3109
- Keywords
- Nap, Endothelial function, Shift work, Nurses
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
On-duty NapBehavioural
For 12 weeks, an opportunity for a 30-minute nap during the night shift, between 1 a.m. and 4 a.m., in a quiet room with facilities for lying down.
Control condition (30-min rest)Behavioural
For 12 weeks, an opportunity for a 30-minute rest during the night shift, between 1 a.m. and 4 a.m., in a quiet room without facilities for lying down or napping.
EndoPATDevice
The EndoPAT device® measures vascular reactivity after a 5-minute occlusion on one arm.
This device measures changes in vascular tone induced by the endothelium at fingertip level using a pair of plethysmographic sensors. The measurement consists of performing a reference recording for 5 minutes on the 2 arms, then a test arm is chosen to perform an occlusion for 5 minutes while continuing the recording.
Popmeter®Device
The tool is connected to the caregiver's finger and toe via photodiode sensors. Its simple operation enables reproducible measurement of the propagation speed of the pulse wave in 14 seconds.
Panasonic EW3109Device
Also called automatic blood pressure device
Diastolic and systolic blood pressure measured 3 times in succession using an automatic blood pressure monitor (Panasonic EW3109) in the sitting position on the left arm.
ECG HolterDevice
Also called portable electrocardiogram
The Holter takes an ECG during the subject's daily activities at home.
Fasting blood sampleBiological
15 ml blood sample (venous sampling) will be taken to measure inflammatory biomarkers (hsCRP, IL-6 TNF-α, IL-1β) and blood markers of endothelial function (NO, CRP, SOD, IL-18).
Pichot fatigue scaleOther
The Pichot fatigue scale is an 8-item questionnaire, with a score above 22 indicating excessive fatigue.
French version of the Recovery Needs Scale (BRD)Other
BRD questionnaire consists of 11 items coded 0 or 1. A score is calculated for each participant, multiplied by 10 to give a score ranging from 0 to 100. The greater the need for recovery, the higher the score.
The Short-Form 36 (SF-36)Other
The SF-36 questionnaire is used to assess quality of life. It comprises 8 sub-scores ranging from 0 (minimum quality of life) to 100 (maximum well-being).
Pittsburgh Sleep Quality Index (PSQI)Other
24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality
Epworth questionnaireOther
8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness
The Karolinska Sleepiness ScaleOther
The Karolinska Sleepiness Scale measures daytime sleepiness on a 9-point scale, based on 5 states and 4 intermediate states that are not verbally indicated.
ActimeterDevice
An actimeter will be worn on the non-dominant wrist, uninterrupted day and night, for 7 consecutive days.
| Study group | Role | What they receive |
|---|---|---|
| Nap group | Experimental | The experimental group will be allocated to do a 30-min on-duty nap during night work, in a dedicated room between 1 am and 4 am. Receives: Behavioral: On-duty Nap; Device: EndoPAT; Device: Popmeter®; Device: Panasonic EW3109; Device: ECG Holter; Biological: Fasting blood sample; Other: Pichot fatigue scale; Other: French version of the Recovery Needs Scale (BRD); Other: The Short-Form 36 (SF-36); Other: Pittsburgh Sleep Quality Index (PSQI); Other: Epworth questionnaire; Other: The Karolinska Sleepiness Scale; Device: Actimeter |
| Control group | Active comparator | The control group will be allocated to rest in a dedicated room without napping between 1 am and 4 am. Receives: Behavioral: Control condition (30-min rest); Device: EndoPAT; Device: Popmeter®; Device: Panasonic EW3109; Device: ECG Holter; Biological: Fasting blood sample; Other: Pichot fatigue scale; Other: French version of the Recovery Needs Scale (BRD); Other: The Short-Form 36 (SF-36); Other: Pittsburgh Sleep Quality Index (PSQI); Other: Epworth questionnaire; Other: The Karolinska Sleepiness Scale; Device: Actimeter |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evolution of reactive hyperemia index (RHI)
RHI is measured through the EndoPAT device® initially and at 12 weeks, and corresponds to the vascular reactivity following a 5-min occlusion on an arm
Measured: Change between week 1 and 12
Secondary outcomes (13)
Evolution of pulse wave velocity (PWV)
PWV is measured through the Popmeter® initially and at 12 weeks, and corresponds to the finger-o-foot pulse wave velocity(m/s)
Measured: Change between week 1 and 12
Evolution of blood pressure
Systolic and diastolic blood pressure (mm Hg) measured in the sitting position in triplicate with an automatic blood pressure device (Panasonic EW3109) on the left arm, initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of heart rate variability (HRV)
24-h Holter-Electrocardiogram to derive temporal (SDNN, rMSSD, pNN50) and frequency (LF, HF, LF/HF) HRV indices initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of pro-inflammatory biomarkers
Fasting blood sample to measure hsCRP, IL-6 TNF-α, IL-1β initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of blood markers of endothelial function
Fasting blood sample to measure NO, SOD, IL-18 initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of subjective Fatigue
The Pichot fatigue scale (composed of 8 items, a score above 22 indicates excessive fatigue), initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of recovery Needs
French version of the Recovery Needs Scale (BRD), initially and at 12 weeks, wich consists of 11 items coded 0 or 1. A score is calculated for each participant, multiplied by 10 to give a score ranging from 0 to 100. The greater the need for recovery, the higher the score.
Measured: Change between week 1 and 12
Evolution of state of health
The SF-36 questionnaire is used to assess quality of life, initially and at 12 weeks. It comprises 8 sub-scores ranging from 0 (minimum quality of life) to 100 (maximum well-being).
Measured: Change between week 1 and 12
Evolution of sleep quality
Pittsburgh Sleep Quality Index (PSQI), initially and at 12 weeks : 24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality.
Measured: Change between week 1 and 12
Evolution of subjective sleepiness
Epworth questionnaire, initially and at 12 weeks : 8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness
Measured: Change between week 1 and 12
Evolution of alertness at work assessed
The Karolinska Sleepiness Scale measures daytime sleepiness on a 9-point scale, based on 5 states and 4 intermediate states that are not verbally indicated, initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of sleep time
Actimeter measuring variations in wake-up and bedtimes, sleep duration, energy expenditure and time spent at different levels of physical activity intensity (sedentary, light intensity, moderate to intense intensity), initially and at 12 weeks.
Measured: Change between week 1 and 12
Evolution of sleep duration
Actimeter measuring variations in wake-up and bedtimes, sleep duration, energy expenditure and time spent at different levels of physical activity intensity (sedentary, light intensity, moderate to intense intensity), initially and at 12 weeks.
Measured: Change between week 1 and 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Jul 2023
- Study start19 Feb 2024
- Primary completion26 Sep 2025
- Study completion22 Dec 2025
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 Healthy VolonteersStudies of the same condition, open and under way.
- More trials run by Centre Hospitalier Universitaire de Saint EtienneThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Frédéric ROCHE, MD PhD, Principal investigator, Centre Hospitalier Universitaire de Saint Etienne
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05955729
- Sponsor's protocol ID
- 23CH138
- Other IDs
- 2023-A01109-36
- Acronym
- NAP-WORK
- Status last verified
- Jan 2026
- First submitted
- 23 Jun 2023
- Last updated
- 13 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Bouchou Y, Monnier M, Roche F, Pelissier C, Berger M. Effect of 12 weeks with a 30-min nap opportunity during the night shift of healthcare workers on early cardiovascular risk biomarkers: the NAPWORK study protocol of a randomised controlled trial. BMJ Open. 2026 Jan 22;16(1):e110108. doi: 10.1136/bmjopen-2025-110108.
PubMed 41571410
Study at a glance
From the registry record, last updated by the sponsor on 13 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of a Short Nap During the Night Shift of Healthcare Workers on Endothelial Function: NAP-WORK Randomized Controlled Study
- ClinicalTrials.gov ID
- NCT05955729
- Acronym / sponsor ID
- NAP-WORK / 23CH138
- Conditions
- Healthy Volonteers
- Keywords
- Nap, Endothelial function, Shift work, Nurses
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- Centre Hospitalier Universitaire de Saint EtienneUniversity, hospital or other
- Study start
- 19 Feb 2024 (actual)
- Primary completion
- 26 Sep 2025 (actual)
- Study completion
- 22 Dec 2025 (actual)
- First posted
- 21 Jul 2023 (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.
Night shift work is well known to cause health disruption in short and long term. It has been reported that among healthcare workers, nurses slept less than 6 h/24h. Consequences of such short sleep duration has been associated to long term issues such as endothelial dysfunction associated with cardiovascular diseases, arterial hypertension and type 2 diabetes. Countermeasures such as nap at work has potential effects on reducing the prevalence of cardiovascular diseases. However, to our knowledge, no studies have objectively investigated the effects of napping on endothelial function in a longitudinal design. Therefore, this study aims to investigate the effect of a 30 minutes on-duty nap during night work for 12 weeks on caregivers endothelial dysfunction.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Nap group | Experimental | Behavioral: On-duty Nap, Device: EndoPAT, Device: Popmeter®, Device: Panasonic EW3109, Device: ECG Holter, Biological: Fasting blood sample, Other: Pichot fatigue scale, Other: French version of the Recovery Needs Scale (BRD), Other: The Short-Form 36 (SF-36), Other: Pittsburgh Sleep Quality Index (PSQI), Other: Epworth questionnaire, Other: The Karolinska Sleepiness Scale, Device: ActimeterThe experimental group will be allocated to do a 30-min on-duty nap during night work, in a dedicated room between 1 am and 4 am. |
| Control group | Active comparator | Behavioral: Control condition (30-min rest), Device: EndoPAT, Device: Popmeter®, Device: Panasonic EW3109, Device: ECG Holter, Biological: Fasting blood sample, Other: Pichot fatigue scale, Other: French version of the Recovery Needs Scale (BRD), Other: The Short-Form 36 (SF-36), Other: Pittsburgh Sleep Quality Index (PSQI), Other: Epworth questionnaire, Other: The Karolinska Sleepiness Scale, Device: ActimeterThe control group will be allocated to rest in a dedicated room without napping between 1 am and 4 am. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Being a paramedical caregiverr (nurse or care assistant) at Saint-Etienne University Hospital
- Be aAged between 18 and 65
- Working at least 80% of a full-time equivalent post
- Working 12-hour shifts (day/night) in continuous care services
- Being affiliated or entitled under a social security scheme
Key exclusion criteria (6 listed)
- Have made a tTrans meridian journey in the last month prior to the study
- Have a mMedically diagnosed sleep disorder such asof the hypersomnia or insomnia type
- Have a diagnosed and treated mental pathology
- Usually take a nap in the workplace in a quiet room
- Be pregnant or breastfeeding
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 |
|---|---|---|
| On-duty NapFor 12 weeks, an opportunity for a 30-minute nap during the night shift, between 1 a.m. and 4 a.m., in a quiet room with facilities for lying down. | Behavioural | Nap group |
| Control condition (30-min rest)For 12 weeks, an opportunity for a 30-minute rest during the night shift, between 1 a.m. and 4 a.m., in a quiet room without facilities for lying down or napping. | Behavioural | Control group |
| EndoPATThe EndoPAT device® measures vascular reactivity after a 5-minute occlusion on one arm. This device measures changes in vascular tone induced by the endothelium at fingertip level using a pair of plethysmographic sensors. The measurement consists of performing a reference recording for 5 minutes on the 2 arms, then a test arm is chosen to perform an occlusion for 5 minutes while continuing the recording. | Device | Control group, Nap group |
| Popmeter®The tool is connected to the caregiver's finger and toe via photodiode sensors. Its simple operation enables reproducible measurement of the propagation speed of the pulse wave in 14 seconds. | Device | Control group, Nap group |
| Panasonic EW3109Also: automatic blood pressure deviceDiastolic and systolic blood pressure measured 3 times in succession using an automatic blood pressure monitor (Panasonic EW3109) in the sitting position on the left arm. | Device | Control group, Nap group |
| ECG HolterAlso: portable electrocardiogramThe Holter takes an ECG during the subject's daily activities at home. | Device | Control group, Nap group |
| Fasting blood sample15 ml blood sample (venous sampling) will be taken to measure inflammatory biomarkers (hsCRP, IL-6 TNF-α, IL-1β) and blood markers of endothelial function (NO, CRP, SOD, IL-18). | Biological | Control group, Nap group |
| Pichot fatigue scaleThe Pichot fatigue scale is an 8-item questionnaire, with a score above 22 indicating excessive fatigue. | Other | Control group, Nap group |
| French version of the Recovery Needs Scale (BRD)BRD questionnaire consists of 11 items coded 0 or 1. A score is calculated for each participant, multiplied by 10 to give a score ranging from 0 to 100. The greater the need for recovery, the higher the score. | Other | Control group, Nap group |
| The Short-Form 36 (SF-36)The SF-36 questionnaire is used to assess quality of life. It comprises 8 sub-scores ranging from 0 (minimum quality of life) to 100 (maximum well-being). | Other | Control group, Nap group |
| Pittsburgh Sleep Quality Index (PSQI)24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality | Other | Control group, Nap group |
| Epworth questionnaire8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness | Other | Control group, Nap group |
| The Karolinska Sleepiness ScaleThe Karolinska Sleepiness Scale measures daytime sleepiness on a 9-point scale, based on 5 states and 4 intermediate states that are not verbally indicated. | Other | Control group, Nap group |
| ActimeterAn actimeter will be worn on the non-dominant wrist, uninterrupted day and night, for 7 consecutive days. | Device | Control group, Nap group |
Primary outcome
Evolution of reactive hyperemia index (RHI)
Time frame: Change between week 1 and 12
RHI is measured through the EndoPAT device® initially and at 12 weeks, and corresponds to the vascular reactivity following a 5-min occlusion on an arm
13 secondary outcomes
Evolution of pulse wave velocity (PWV)
Time frame: Change between week 1 and 12
Evolution of blood pressure
Time frame: Change between week 1 and 12
Evolution of heart rate variability (HRV)
Time frame: Change between week 1 and 12
Evolution of pro-inflammatory biomarkers
Time frame: Change between week 1 and 12
Evolution of blood markers of endothelial function
Time frame: Change between week 1 and 12
Evolution of subjective Fatigue
Time frame: Change between week 1 and 12
Evolution of recovery Needs
Time frame: Change between week 1 and 12
Evolution of state of health
Time frame: Change between week 1 and 12
Evolution of sleep quality
Time frame: Change between week 1 and 12
Evolution of subjective sleepiness
Time frame: Change between week 1 and 12
Evolution of alertness at work assessed
Time frame: Change between week 1 and 12
Evolution of sleep time
Time frame: Change between week 1 and 12
Evolution of sleep duration
Time frame: Change between week 1 and 12
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 13 Jan 2026.
- Derived from this study: PubMed 41571410Bouchou Y, Monnier M, Roche F, Pelissier C, Berger M. Effect of 12 weeks with a 30-min nap opportunity during the night shift of healthcare workers on early cardiovascular risk biomarkers: the NAPWORK study protocol of a randomised controlled trial. BMJ Open. 2026 Jan 22;16(1):e110108. doi: 10.1136/bmjopen-2025-110108.
- Individual participant dataSharing planned: No
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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.
Frédéric ROCHE, MD PhD principal investigator
Centre Hospitalier Universitaire de Saint Etienne
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing On-duty Nap, EndoPAT and Popmeter® in people with Healthy Volonteers, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
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 6 inclusion and 6 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 13 Jan 2026. 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 France. 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?
Evolution of reactive hyperemia index (RHI) (time frame: Change between week 1 and 12). 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 NCT05955729, 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 13 Jan 2026.