Lack of funding.

The overarching goal of this study is to mimic a night shift work like schedule and characterize circadian variation in Pulse Wave Velocity (PWV), a measure of arterial stiffness, and determine the impact of acute loss of sleep like that experienced by shift workers on PWV.

Night shift work is associated with increased risk of cardiovascular disease (CVD). Pulse wave velocity (PWV) is a commonly used non-invasive measure of arterial stiffness and is strongly associated with CVD. Previous research links sleep loss, like that experienced by shift workers, to elevated levels or abnormal levels of PWV. In addition, there is some research that shows circadian variation in PWV, which has implications for future studies and when PWV should be assessed. The overarching goal of this study is to characterize circadian variation in PWV and determine the impact of acute loss of sleep on PWV during a schedule like that experienced by night shift workers.

Inclusion Criteria:

An individual may be eligible to participate if they meet the following criteria:

1. are between the ages of 20 and 29 years;
2. have not been diagnosed or told by a healthcare clinician that they have a medical condition that may impact their blood pressure or cardiovascular health/system;
3. can abstain from smoking tobacco or chewing tobacco products;
4. can abstain from caffeine and exercise for 4 days in a row;
5. are not prescribed medications or take over the counter medications that may impact blood pressure or heart rate (a team physician will review any reported medications identified during screening);
6. do not have a physical condition that may interfere with using the upper arm, upper thigh, or access to the neck area for purposes of performing non-invasive measures linked to this protocol; and
7. feel that they can avoid working and complete the 4 day protocol without interruption.

Exclusion Criteria:

An individual will be excluded if they report:

1. a medical condition or diagnosis that may impact their blood pressure or heart rate;
2. taking any standing medications or prescriptions, other than over the counter medications or contraceptives, that may impact their blood pressure or heart rate;
3. are unable to adhere to a strict 4 day protocol that involves abstaining from caffeine, alcohol, tobacco products (nicotine), and exercise;
4. have a physical condition that may limit use of the upper arm or upper thigh or area around the neck, which is necessary for performing multiple non-invasive measures associated with this protocol.
5. being pregnant.

Because participants may awaken during the in-lab sleep opportunity when staff use the Sphygmocor device, it is important that staff and the study team know if the participant has ever experienced the following:

A] Sleep Paralysis; B] Night Terrors; C] Have Obstructive Sleep Apnea which requires the use of a CPAP Device; D] Become angry towards others when abruptly woken up; E] Become physical towards others when abruptly woken up.

Investigators do not have a defined plan to share data with outside investigators.