(China Daily)
Updated: 2008-02-27 10:45

It recurs at regular intervals, over and over again: The fluttering sound of "sawing logs" that often robs sleep from the partners of snorers.

The habit is not merely annoying. "It can even be a health risk," notes Volker Schilling, chief physician for head and throat surgery and disorders of the ears, nose and throat at the Vivantes Clinic in Berlin's Neukoelln district.

Snoring results from an obstruction to the flow of air through passages at the back of the mouth and nose. When muscles in the soft palate and uvula are relaxed, they can vibrate noisily as the sleeper breathes.

Certain factors contribute to snoring, Schilling says, "such as being overweight or having a late, heavy meal, which busies the body with digestion".

About 2 percent of snorers suffer from a dangerous disorder called sleep apnea. "Apnea is a constriction of the upper respiratory tract, causing breathing to stop for several seconds, or up to a minute and a half," explains Winfried Randerath, a sleep physician from the German city of Solingen.

Muscles go slack, and the tongue - a large muscle - falls backward into the throat, blocking it. "This cuts off the airway and leads to an oxygen deficiency in the blood," says Schilling, who adds that an affected person's muscles then tense, bringing him or her out of a deep sleep into a lighter one.

Apnea can be diagnosed in a sleep laboratory. Sufferers usually go to a doctor first and complain of general ill-being. "The patients are usually tired in the morning - absolutely exhausted - although they say that they slept during the night," remarks Susanne Schwarting, president of the Berlin-based German Society of Dental Sleep Medicine.

"Daytime drowsiness can also lead to life-threatening situations," Schwarting says, such as falling asleep for several seconds when driving a car. Moreover, the release of stress hormones puts a greater strain on the cardiovascular systems of apnea patients than on those of others.

According to Randerath, there are numerous remedies for annoying, but harmless, snoring, as well as for apnea. They include throat lubricants and nasal strips to keep the nose open, and they are usually touted in glowing terms. "Only a few forms of therapy have been scientifically proven to be effective, however," Schwarting says.

In severe cases of apnea, the standard therapy is an oxygen mask that works like a vacuum cleaner in reverse. "Continuous positive airway pressure prevents the muscles from relaxing," Randerath says.

A treatment for harmless snoring, as well as for light and medium cases of sleep apnea, is a mandibular advancement splint, which resembles a plastic orthodontic brace.

"The splint pulls the lower jaw - and the tongue along with it - slightly forward, preventing the tongue from blocking the airway during sleep," Schwarting says.

There are also surgical procedures to cure snoring and apnea, but they are not always successful.

(China Daily 02/27/2008 page19)