Effect of a Short Nap During the Night Shift of Healthcare Workers on Endothelial Function

Study Overview
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Brief Summary
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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.

Official Title
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Effect of a Short Nap During the Night Shift of Healthcare Workers on Endothelial Function: NAP-WORK Randomized Controlled Study

Conditions
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Healthy Volonteers

Intervention / Treatment
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* Behavioral: On-duty Nap
* 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: Dreem Headband
* Device: Actimeter


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 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 Exclusion Criteria: 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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Nap group<br>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. | Behavioral: On-duty Nap<br>* 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.<br>Device: EndoPAT<br>* 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.<br>Device: Popmeter®<br>* 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.<br>Device: Panasonic EW3109<br>* 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.<br>* Other names: automatic blood pressure device;Device: ECG Holter<br>* The Holter takes an ECG during the subject's daily activities at home.<br>* Other names: portable electrocardiogram;Biological: Fasting blood sample<br>* A 5 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).<br>Other: Pichot fatigue scale<br>* The Pichot fatigue scale is an 8-item questionnaire, with a score above 22 indicating excessive fatigue.<br>Other: French version of the Recovery Needs Scale (BRD)<br>* 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.<br>Other: The Short-Form 36 (SF-36)<br>* 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).<br>Other: Pittsburgh Sleep Quality Index (PSQI)<br>* 24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality<br>Other: Epworth questionnaire<br>* 8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness<br>Other: The Karolinska Sleepiness Scale<br>* 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.<br>Device: Dreem Headband<br>* A connected sleep band (Dreem Headband), which measures sleep duration, sleep patterns and sleep quality, will be worn during night-time sleep at home and naps at work.<br>Device: Actimeter<br>* An actimeter will be worn on the non-dominant wrist, uninterrupted day and night, for 7 consecutive days.<br>|
| Active Comparator: Control group<br>The control group will be allocated to rest in a dedicated room without napping between 1 am and 4 am. | Behavioral: Control condition (30-min rest)<br>* 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.<br>Device: EndoPAT<br>* 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.<br>Device: Popmeter®<br>* 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.<br>Device: Panasonic EW3109<br>* 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.<br>* Other names: automatic blood pressure device;Device: ECG Holter<br>* The Holter takes an ECG during the subject's daily activities at home.<br>* Other names: portable electrocardiogram;Biological: Fasting blood sample<br>* A 5 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).<br>Other: Pichot fatigue scale<br>* The Pichot fatigue scale is an 8-item questionnaire, with a score above 22 indicating excessive fatigue.<br>Other: French version of the Recovery Needs Scale (BRD)<br>* 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.<br>Other: The Short-Form 36 (SF-36)<br>* 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).<br>Other: Pittsburgh Sleep Quality Index (PSQI)<br>* 24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality<br>Other: Epworth questionnaire<br>* 8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness<br>Other: The Karolinska Sleepiness Scale<br>* 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.<br>Device: Actimeter<br>* An actimeter will be worn on the non-dominant wrist, uninterrupted day and night, for 7 consecutive days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | Change between week 1 and 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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) | 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. | 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. | Change between week 1 and 12 | 
| Evolution of pro-inflammatory biomarkers | Fasting blood sample (5 mL) to measure hsCRP, IL-6 TNF-α, IL-1β initially and at 12 weeks. | Change between week 1 and 12 | 
| Evolution of blood markers of endothelial function | Fasting blood sample (5 mL) to measure NO, SOD, IL-18 initially and at 12 weeks. | 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. | 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. | 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). | 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. | 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 | 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. | Change between week 1 and 12 | 
| Evolution of sleep time | A connected sleep band (Dreem Headband), which measures sleep duration, sleep patterns and sleep quality, will be worn during night-time sleep at home and naps at work, initially and at 12 weeks. | 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. | Change between week 1 and 12 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Nap, Endothelial function, Shift work, Nurses