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

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05955729
Acronym
NAP-WORK
Enrollment
80
Registered
2023-07-21
Start date
2024-02-19
Completion date
2025-12-22
Last updated
2026-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volonteers

Keywords

Nap, Endothelial function, Shift work, Nurses

Brief 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 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.

Interventions

BEHAVIORALOn-duty Nap

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.

BEHAVIORALControl 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.

DEVICEEndoPAT

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.

DEVICEPopmeter®

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.

DEVICEPanasonic EW3109

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.

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

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).

OTHERPichot fatigue scale

The Pichot fatigue scale is an 8-item questionnaire, with a score above 22 indicating excessive fatigue.

OTHERFrench 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.

OTHERThe 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).

24-question sleep quality assessment scale, a score \> 5 indicates poor sleep quality

OTHEREpworth questionnaire

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

OTHERThe Karolinska Sleepiness Scale

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.

DEVICEActimeter

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

Sponsors

Centre Hospitalier Universitaire de Saint Etienne
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Evolution of reactive hyperemia index (RHI)Change between week 1 and 12RHI 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

MeasureTime frameDescription
Evolution of blood pressureChange between week 1 and 12Systolic 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.
Evolution of heart rate variability (HRV)Change between week 1 and 1224-h Holter-Electrocardiogram to derive temporal (SDNN, rMSSD, pNN50) and frequency (LF, HF, LF/HF) HRV indices initially and at 12 weeks.
Evolution of pro-inflammatory biomarkersChange between week 1 and 12Fasting blood sample to measure hsCRP, IL-6 TNF-α, IL-1β initially and at 12 weeks.
Evolution of blood markers of endothelial functionChange between week 1 and 12Fasting blood sample to measure NO, SOD, IL-18 initially and at 12 weeks.
Evolution of subjective FatigueChange between week 1 and 12The Pichot fatigue scale (composed of 8 items, a score above 22 indicates excessive fatigue), initially and at 12 weeks.
Evolution of recovery NeedsChange between week 1 and 12French 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.
Evolution of pulse wave velocity (PWV)Change between week 1 and 12PWV is measured through the Popmeter® initially and at 12 weeks, and corresponds to the finger-o-foot pulse wave velocity(m/s)
Evolution of sleep qualityChange between week 1 and 12Pittsburgh Sleep Quality Index (PSQI), initially and at 12 weeks : 24-question sleep quality assessment scale, a score \> 5 indicates poor sleep quality.
Evolution of subjective sleepinessChange between week 1 and 12Epworth questionnaire, initially and at 12 weeks : 8-question sleepiness assessment scale, a score above 10 indicates excessive sleepiness
Evolution of alertness at work assessedChange between week 1 and 12The 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.
Evolution of sleep timeChange between week 1 and 12Actimeter 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.
Evolution of sleep durationChange between week 1 and 12Actimeter 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.
Evolution of state of healthChange between week 1 and 12The 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).

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026