Evidence suggests a relationship between sleep deprivation and cardiovascular disease. The investigators wish to determine whether 9 nights of modest sleep restriction results in activation of cardiovascular disease mechanisms, thus potentially increasing the risk of cardiovascular disease. The investigators hypothesize that sleep restriction will result in elevated blood pressure, inflammation, and neurocognitive deficits.

Evidence suggests a relationship between sleep deprivation and cardiovascular disease. Voluntary sleep restriction is common, with 28% of the US adult population reports getting 6 or fewer hours of sleep per night, and those who do are 24% more likely to have cardiovascular disease and have twice the risk of hypertension. Insufficient sleep may conceivably be one of the most common, and most preventable, cardiovascular risk factors. The investigators wish to determine whether 9 nights of modest sleep restriction results in activation of cardiovascular disease mechanisms, thus potentially increasing the risk of cardiovascular disease. The investigators will combine our cardiovascular studies with state-of-the art sleep monitoring and neurocognitive tests to provide unambiguous data on the physiologic effects of sleep restriction. Together, the investigators findings will help explain whether the reduced sleep duration in the general population may be contributing to the current epidemic of cardiovascular disease, and suggest strategies to reduce this risk.

Inclusion Criteria:

• Age 18-40 years
• No chronic medical conditions other than seasonal or environmental allergies
• On no prescription medications other than second generation antihistamines (Cetirizine, Fexofenadine, Desloratadine, Loratadine, etc), oral contraceptive pills, or intrauterine devices.
• BMI 18.5-35 kg/m2
• Both normotensive and prehypertensive people are eligible and will be studied
• Not a current smoker or tobacco user
• Not pregnant or breast feeding and not intending to become pregnant or breast feed

Exclusion Criteria:

• The investigators will exclude subjects who have any medical or psychiatric disorders
• History of anxiety or depression, and those taking any medications other than non-sedating antihistamines or oral contraceptives.
• Those found to have depression on a depression screening tool (BDI-II) will be excluded. Current smokers will be excluded.
• All female subjects will undergoing a screening pregnancy test and excluded if positive.
• Subjects found to have significant sleep disorders will be excluded.