Consequences of Insufficient Sleep: Your Achy Breaky Heart
Just 24 hour of wakefulness can have profound consequences for your cardiovascular health. Losing out on this period of restoration inhibits proper down regulation of many systems and can also lead to dysfunction while one is awake. Anyone who has gone without sleep for a prolonged period of time has undoubtedly experienced the cognitive issues and performance decrements associated with a sleep-deprived state. However, the cardiovascular consequences may be less obvious to our perception. Experimental studies have shown effects on the following parameters after just 24–40 hours of total sleep deprivation in healthy individuals.
During sleep, blood pressure is normally reduced, termed “nocturnal dipping.” This decrease serves a healthy homeostatic function for humans . Inadequate sleep quantity or quality leads to an increase in blood pressure both during the night, as well as throughout the following day, most likely due to an increase in sympathetic activity (again, your “fight or flight” is constantly on, not a good thing). Accompanying this increase in blood pressure is an increase in heart rate — both at rest and most likely during any physical activity you might do the following day.
Inflammation is the body’s normal physiological immune response — mounting defensive molecules when an external stressor (e.g. virus or pathogen) is present. Improper inflammatory activation, either chronic or acute, is related to cardiovascular disease development and a slew of other metabolic disorders. During sleep deprivation, a variety of inflammatory markers increase: TNF-alpha, IL-6, C-reactive protein. Many of these (such as CRP) are independent predictors of cardiovascular disease and events. Inflammation leads to oxidative stress, and over time (situations of chronic sleep loss), this is a perfect primer for the development of cardiovascular disease development, among other disorders associated with low-grade inflammation.