Blood Vessel Function
The ability of your blood vessels to dilate is key in maintaining cardiovascular health, regulating blood pressure, and preventing development of disease. Asessment of blood vessel health in research involves subjecting the arteries to numerous stimuli, such as a large increase in blood flow to the arm, termed “reactive hyperemia,” or various agents such as sodium nitroprusside or even heat, which lead to the relaxation (vasodilation) or arteries. The responsiveness of the arteries to these stimuli tells us a lot about the health of the blood vessels. A decrease in function is often seen in many diseases such as CVD, obesity, and diabetes.
Sleep loss, whether acute or chronic, leads to a decrease in reactivity of blood vessels. Vascular conductance, one measure of micro-vessel reactivity, decreases after just 29 hours without sleep. This may be due to an increase in inflammation, a decrease in responsiveness of your vascular smooth muscle to certain molecules, or a heightened sympathetic activity (or likely, a combination of all of these). The body simply becomes less able to regulate blood vessel function properly. The consequence of this is that overall, we are able to less effectively perfuse our organs, tissues, and CV system. This is not insignificant — as endothelial function is directly related to cardiovascular disease risk, and even independently predicts disease development. Endothelial dysfunction after sleep loss, mirror that which occurs in numerous diseases, illustrates just how detrimental it may be.