HEALTH REPORT - Sleep Apnea Linked to Increased Stroke Risk

（单词翻译）

HEALTH REPORT - Sleep Apnea Linked to Increased Stroke Risk
By Cynthia Kirk

Broadcast: Wednesday, November 30, 2005

I'm Steve Ember with the VOA Special English Health Report.

Sleep apnea is a common disorder¹. Experts say it affects about eighteen million Americans. People with sleep apnea stop breathing for brief periods while they sleep. They may awaken² for a few seconds as they struggle to breathe. The next day, the sleeper³ may not remember what happened.

 
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Signs of the disorder include sleepiness during the day and restless sleep. Some people make rough sounds while they sleep. More men have sleep apnea than women do. It is also common in older adults and in persons who are heavy.

Obstructive sleep apnea is the most common form. It happens when soft tissue in the back of the throat blocks the flow of air. Another form is called central sleep apnea. This results from problems with the brain's normal signals to breathe.

Left untreated, sleep apnea can be life threatening. People may get sleepy while at work or driving. Many people do not know they have it until they are tested in a sleep laboratory and treated.

Studies have linked sleep apnea to more severe problems. A recent study at the Yale University School of Medicine showed that people with obstructive sleep apnea are two times more likely to die from strokes. The risk is linked to the severity of sleep apnea.

Sleep apnea is also linked to heart disease, high blood pressure, heart attack, and the disease diabetes⁴. Doctors are not sure why. But they suggest that oxygen levels in the blood fall when a person stops breathing. The reduced oxygen increases levels of the hormone⁵ adrenaline in the body. This causes the heart to beat faster and raises blood pressure.

Most treatments for sleep apnea begin with simple changes, such as avoiding alcoholic⁶ drinks, losing weight and stopping smoking. Others may require an operation to remove tissue and widen the airway⁷.

For more severe cases, doctors use continuous positive airway pressure, also known as CPAP (C-PAP). CPAP is a device worn over the nose that connects to a tube. The tube is connected to a small machine that controls air pressure.

Some studies have shown CPAP can improve sleep, reduce sleepiness during daytime hours and lower blood pressure. But a Canadian study found the devices did not improve survival rates among people with central sleep apnea.

This VOA Special English Health Report was written by Cynthia Kirk. I'm Steve Ember.