Long Sleep Duration and Vascular Function

Sleep duration has received much attention in recent years due to strong evidence that not enough sleep can increase risk for a number of diseases and disorders. Research is emerging that too much sleep also has a negative impact on health, particularly higher risk for myocardial infarction and stroke. The investigators hypothesize that long duration sleep has the ability to impair peripheral and cerebral vascular function in middle-aged to older adults.

The aim of this study is to compare the effect of long duration sleep (\>9 hours) to recommended levels of sleep (7-8 hours) in a crossover designed study requiring adults to maintain each prescribed sleep duration for one week. Ambulatory brachial and central aortic blood pressure will be measured during sleep, while cerebrovascular reactivity, carotid artery hemodynamics (e.g., flow pulsatility), aortic pulse wave reflections, cognitive function, and peripheral vasodilatory function will be measured before and after each sleep protocol. A secondary objective of this study is to understand whether aerobic exercise can improve vascular function under conditions of different sleep durations. This information will shed light upon the impact of sleep parameters on exercise-induced improvements in vascular function.