There is considerable evidence that sleep apnea does much more than just disrupt your sleep. Sleep apnea - which commonly occurs in those who snore loudly - is defined by pauses in breathing. This may be caused either by obstruction of the airway or by the brain forgetting to prompt a breath. When this happens, oxygen levels fall, carbon dioxide levels rise, and there is a spike in blood pressure, heart rate, and hormones as the body reawakens to breathe. Sleep apnea has been linked to many chronic medical conditions, and even sudden death.
It is estimated that 50-70% of people with sleep apnea have hypertension, or high blood pressure. This increases the risk for heart attack, stroke, and other health problems. Laboratory experiments in animals have shown a cause-and-effect relationship, with the presence of sleep apnea leading to a later development of hypertension. In people with hard-to-control hypertension, it may be that sleep apnea is contributing.
Coronary Heart Disease
The risk for cardiovascular disease increases due to several mechanisms. Sleep apnea can lead to activation of the sympathetic nervous system. This is responsible for the "fight-or-flight" response. Imagine the stress on your body that occurs when a lion is chasing you, this is the sympathetic nervous system at work. In addition, sleep apnea leads to problems with the lining of blood vessels, inflammation, and problems with metabolic regulation. All of these can cause problems with blood vessels and lead to major problems like a heart attack.
According to research, the association between stroke and sleep apnea is perhaps as strong as the association between smoking and stroke. There may be several factors involved. During apnea, blood vessels within the brain dilate when the oxygen levels fall. Moreover, individuals with sleep apnea have higher levels of blood factors that make them more susceptible to clots that may lead to stroke. Approximately 40-60% of people with stroke are found to have obstructive sleep apnea.
Chronic Heart Failure
When apneic events occur, the decreased levels of oxygen can cause blood vessels in the lungs to constrict. This increases the blood pressure in these vessels, and over time may lead to chronic right-sided heart failure. High blood pressure is a major contributor to left-sided heart failure. Some studies have shown that as many as 37% of people with heart failure may have sleep apnea.
In a study of patients who died suddenly who had had recent sleep studies performed, it was shown that almost half of the patients with sleep apnea died between the hours of midnight to 6 a.m., compared with 21% without sleep apnea. It is possible that these individuals died suddenly during periods of apnea.
The Good News
The good news is that there is effective treatment for sleep apnea, called Continuous Positive Airway Pressure (CPAP), and this can help eliminate many of these risks associated with the disease.
American Sleep Apnea Association. Accessed: February 9, 2014.
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