Night shift work is well known to cause health disruption in the short and long term. Among healthcare workers, sleep deprivation is a common concern with many nurses reporting sleep of

A 12-week randomised controlled trial will be performed with two conditions: (1) a 30 min nap opportunity during night shift work in a dedicated quiet room with a bed and (2) a control condition including a 30 min rest period in a break room. A total of 80 nurses and assistant nurses from interventional care units working a 2x12 hour shift schedule will be recruited. The main outcome will be endothelial dysfunction assessed through the reactive hyperaemia index using the EndoPAT device. Secondary outcomes will include other cardiovascular risk biomarkers, including arterial stiffness (pulse wave velocity), blood pressure, heart rate variability, proinflammatory blood parameters, self-reported fatigue, recovery needs, sleep quality and sleepiness, which will be assessed using validated questionnaires. Our study will address whether napping on the night shift can decrease cardiovascular risk through early cardiovascular biomarkers, including endothelial function, arterial stiffness and heart rate variability. If effective, such interventions could contribute to the development of more sustainable and health-conscious shift work practices, benefiting both workers and the organisations that employ them.

The study protocol is in accordance with ethical principles established by the 18th World Medical Assembly (Helsinki 1964) and received approval from an institutional review board ‘comité de protection des personnes EST III’ (23CH138). Written informed consent will be obtained from all participants.

NCT05955729; ClinicalTrials.gov 2023-A01109-36 Registered on 21 July 2023.