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Completed

NCT Number: NCT05955729

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

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.

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Key information

Conditions

Healthy Volonteers

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Chu de Saint-Etienne

Saint-Etienne, 42055, France

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

On-duty Nap

Behavioral

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)

Behavioral

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.

EndoPAT

Device

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 EW3109

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.

Other names: automatic blood pressure device

ECG Holter

Device

The Holter takes an ECG during the subject's daily activities at home.

Other names: portable electrocardiogram

Fasting blood sample

Biological

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 scale

Other

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 questionnaire

Other

8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness

The Karolinska Sleepiness Scale

Other

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.

Actimeter

Device

An actimeter will be worn on the non-dominant wrist, uninterrupted day and night, for 7 consecutive days.

Primary outcomes

  1. 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

Secondary outcomes

  1. Evolution of pulse wave velocity (PWV)

    Time frame: Change between week 1 and 12

    PWV is measured through the Popmeter® initially and at 12 weeks, and corresponds to the finger-o-foot pulse wave velocity(m/s)

  2. Evolution of blood pressure

    Time frame: Change between week 1 and 12

    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.

  3. Evolution of heart rate variability (HRV)

    Time frame: Change between week 1 and 12

    24-h Holter-Electrocardiogram to derive temporal (SDNN, rMSSD, pNN50) and frequency (LF, HF, LF/HF) HRV indices initially and at 12 weeks.

  4. Evolution of pro-inflammatory biomarkers

    Time frame: Change between week 1 and 12

    Fasting blood sample to measure hsCRP, IL-6 TNF-α, IL-1β initially and at 12 weeks.

  5. Evolution of blood markers of endothelial function

    Time frame: Change between week 1 and 12

    Fasting blood sample to measure NO, SOD, IL-18 initially and at 12 weeks.

  6. Evolution of subjective Fatigue

    Time frame: Change between week 1 and 12

    The Pichot fatigue scale (composed of 8 items, a score above 22 indicates excessive fatigue), initially and at 12 weeks.

  7. Evolution of recovery Needs

    Time frame: Change between week 1 and 12

    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.

  8. Evolution of state of health

    Time frame: Change between week 1 and 12

    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).

  9. Evolution of sleep quality

    Time frame: Change between week 1 and 12

    Pittsburgh Sleep Quality Index (PSQI), initially and at 12 weeks : 24-question sleep quality assessment scale, a score > 5 indicates poor sleep quality.

  10. Evolution of subjective sleepiness

    Time frame: Change between week 1 and 12

    Epworth questionnaire, initially and at 12 weeks : 8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness

  11. Evolution of alertness at work assessed

    Time frame: Change between week 1 and 12

    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.

  12. Evolution of sleep time

    Time frame: Change between week 1 and 12

    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.

  13. Evolution of sleep duration

    Time frame: Change between week 1 and 12

    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.

Sponsors and collaborators

Lead sponsor

Centre Hospitalier Universitaire de Saint Etienne

Other

Registry information

Official study title

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

Acronym: NAP-WORK

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Jul 21, 2023
Registry last updated
Jan 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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