The goal of this observational study is to learn if acutely and/or chronically altered sleep induces inflammation and/or a pro-thrombotic state (a tendency to form clots) in hospital workers who either work in shifts or are exclusively daily workers. The main questions it aims to answer are:

• Does chronically altered sleep induce a pro-inflammatory and pro-thrombotic state, which are steps towards cardiovascular disease, knowing that is associated with poor sleep?
• Does acutely disrupted sleep, such as that observed in night shift workers, induce a pro-inflammatory and pro-thrombotic state in otherwise healthy subjects? Participants in the study are hospital workers who either work in shifts, including night shifts, or only during the day. Sleep quality is assessed by a validated questionnaire (the Pittsburgh Sleep Quality Index). Markers of inflammation and of the pro-thrombotic state are measured at baseline and, if appropriate, after the night shift. These are markers of platelet activation, D-dimer, Interleukin-6 and endothelin 1, known to contribute and/or to suggest a condition of generalized inflammation and a tendency to form clots. Relevant information on health status is also collected for each participant.

Impaired sleep (quantity and quality) is associated with a number of chronic diseases, including an increased risk of cardiovascular events. Some forms of sleep impairment such as insomnia are very frequent and can be easily identified through dedicated and validated questionnaires. The pathway through which impaired sleep heightens cardiovascular risk is not known. Some limited studies suggest activation of coagulation could follow chronic sleep impairment. Atherosclerotic plaque formation is associated with the activation of coagulation, and with chronic inflammation. It would be interesting to know if chronic or acute sleep impairment, such as that experienced by night-shift hospital workers, could induce an inflammatory and pro-thrombotic state either acutely or chronically.

To test whether these hypotheses are correct, volunteer hospital workers who either work in shifts or do not will be enrolled, to test activation of inflammation and hemostasis through established markers (platelet, inflammation and coagulation activation markers). Shift workers will be analyzed before and after a night shift.

Data on anxiety and general health (chronic disorders, medications) as well as on sleep, through validated questionnaires, will be also collected.

Two groups: night-shift workers and daily workers will be compared. Comparisons will be carried out also within night-shift workers, at baseline and after a nigh shift. Finally, subjects who sleep well and who do not sleep well will be compared, independently of shift work.

The investigators believe that if it is shown that insomnia, a frequent and often not addressed sleep disturbance, is associated with a pro-inflammatory and pro-thrombotic state in otherwise healthy workers, this finding would have important consequences, first of all in designing prospective studies on the development of cardiovascular disease in altered sleep and its prevention.

Inclusion Criteria:

• Hospital worker who either works in shifts including night shifts, or only during the day

Exclusion Criteria:

• Known sleep disorder diagnosed by polysomnography and/or nocturnal saturation study
• Sleep apnea-hypopnea syndrome in C-PAP (Continuous Positive Airway Pressure) treatment
• Chronic treatment with sleep-inducers
• Chronic heart failure class NYHA III and IV
• Ischemic heart disease
• Venous thromboembolism
• Chronic anticoagulant and/or anti-platelet therapy

Hospital workers who volunteer for the study