How does sleep apnea cause hypertension?

Sleep apnea can cause hypertension. Doing sleep apnea there is airway obstruction, the patient is unable to breathe in oxygen and to exhale carbon dioxide, resulting in low levels of oxygen and increased levels of carbon dioxide in the blood. The reduction in oxygen and increase in carbon dioxide alert the brain to resume breathing and cause arousal.

With each arousal a signal is sent from the brain to the upper airway muscles to open the airway; breathing is resumed, often with loud snort or gasp. Frequent arousals, although necessary for breathing to restart, prevent the patient from getting enough restorative deep sleep. The arousals are very short and most patients do not recall them.

Due to the serious disturbances in their normal sleep patterns, people with airway obstruction during sleep often feel very sleepy during the day and their concentration and daytime performance suffer. The consequences of this sleep disorder range from annoying to life threatening. They include symptoms suggesting depression, irritability, sexual dysfunction, learning and memory difficulties, and falling asleep when the patient does not want to.

It has been estimated that up to 50% of patients with obstructive sleep apnea have high blood pressure or hypertension. Fifty to sixty percent of patients with impaired heart function suffer from sleep related breathing disorders. If left untreated, obstructive sleep apnea can cause hypertension, irregular heart beat, heart attack, stroke, motor vehicle and work related accidents due to sleepiness (the risk of motor vehicle accident is three times higher in patients with sleep apnea compared to normal), and poor quality of life.

If you suspect that you or anyone in your family suffers from sleep apnea, it is critical that you see a sleep specialist. Sleep medicine is a recognized medical subspecialty. Doctors who specialize in sleep medicine help people who are unable to sleep well. Sleep doctors are able to detect and treat both common and rare sleep disorders. Some common sleep disorders are insomnia, jet lag, sleepwalking, snoring and obstructive sleep apnea.

Several surgical techniques have been developed to increase the size of the airway and hence treat airway obstruction. In children with airway obstruction, surgery is generally the treatment of choice in most of them. However, in adults, the success rate is variable and depends on the experience of the medical center and the surgeon. The long-term side effects and benefits of most surgical procedures are not known yet and it is difficult to predict which patients will do well. It is important for patients to realize that surgery may eliminate snoring but not necessarily airway obstruction. Therefore, all patients should have a follow up overnight sleep study after surgery.

So, sleep apnea can cause hypertension, so it should be taken care of as soon as possible.

Information resource: Dr. Ahmed BaHammam
Director Sleep Disorders Center King Khalid University Hospital
Associate Professor, College of Medicine, King Saud University