Summarizes health considerations and risks associated with sleep apnea.
Repeated airway collapses during sleep result in less oxygen reaching the blood stream. Your body reacts to the reduced oxygen by releasing adrenaline and other hormones into the blood to “jolt” you awake, for survival. As you start to awaken, you gasp to restore breath, and the airway opens up again.
In people with OSA, this series of events happens many times per hour, throughout the night. If you have severe OSA, it can occur hundreds of times per night. Unfortunately, the repeated release of these hormones has negative effects over time.
The partial awakenings triggered by adrenaline interrupt the normal sleep pattern, so that sleep is fragmented and restless. People with OSA wake up tired and are often sleepy throughout the day, having a tendency to fall asleep at work or in the car. The long term effects of non-restful sleep can cause irritability and can slow down thinking. People with OSA are more likely to be forgetful and/or depressed.
You may have heard about the “fight or flight” response for survival: when facing a predator, we must either run or prepare for battle. Adrenaline causes the heart to beat more rapidly and forcefully, to prepare for fight or flight. It also makes the blood more likely to clot, a good thing if injured, and stimulates the inflammatory cell response, in case there is a wound.
However, when the release of adrenaline is sustained over time, as it is in OSA, it can be detrimental. Adrenaline raises the heart rate and blood pressure; over time this increases the risk of a heart attack, stroke, or heart failure. The effect on clotting also increases the risk for heart attack and stroke. Inflammation can alter the lining of blood vessels and promote atherosclerosis, which leads to hardening and narrowing of the arteries, which can lead to blockage, again resulting in heart attack or stroke.
Adrenaline also causes an increase in another hormone — cortisol – a substance that increases the appetite and blood sugar, so excess adrenalin can make weight gain and diabetes more likely.
Studies have also shown that the repeated episodes of lowered blood oxygen that occur during OSA increase the risk of diabetes by altering the body’s response to its own natural insulin.
Exercise and weight reduction are important in preventing and treating type II diabetes – the form of diabetes that affects adults, especially those who are overweight. But it’s not always easy for people to exercise regularly and this becomes even more difficult in people with OSA, when they already feel tired or fatigued. Therefore people with OSA are prone to be less active and gain more weight, creating a vicious cycle of worsening disease.
In addition to the impact of OSA on high blood pressure, heart failure, diabetes, and weight gain, recent studies have shown that untreated OSA and poor sleep quality are linked to a greater risk of developing dementia and Alzheimer’s disease as people age.
Thus, OSA negatively impacts your quality of life and can cause or worsen other serious diseases. The good news is that if OSA is recognized and treated, this cycle can be broken or avoided.