July 31, 2002 -- Sleep apnea not only keeps its sufferers awake at night, but the disorder could put their hearts at risk. A new study shows that middle-aged men who have obstructive sleep apnea are five times more likely than those who don't to develop heart disease. But effective treatment of the disorder may help reduce that risk.
The study results are published in the most recent issue of the American Journal of Respiratory and Critical Care Medicine.
People with sleep apnea briefly stop breathing during sleeping, causing oxygen levels in their blood to drop, and waking them. It's usually due to a blockage or obstruction in the nose or mouth and can, but doesn't always, cause snoring. According to researchers, the problem affects about 24% of middle-aged men and 9% of women in the U.S.
Although several recent studies have suggested a link between sleep apnea and heart disease, a direct cause and effect relationship has not yet been proved. But study author Yüksel Peker, MD, PhD, of Sahlgrenska University Hospital in Gothenberg, Sweden, and colleagues say many of those previous studies didn't take other risk factors into account or lacked adequate follow-up.
In their study, researchers compared a group of middle-aged men who had sleep apnea and a similar group who did not, tracking their health from 1991 to 1998. At least one heart-related problem occurred in 22 of the 60 men with sleep apnea, compared with only eight of the 122 healthy men.
Those men with sleep apnea who suffered from excessive daytime sleepiness were offered treatment -- either a breathing device that provides continuous air pressure during sleep, surgery, or an oral appliance.
The study found that intervention dramatically reduced the risk of heart disease in men with the condition. Twenty-one out of 37 untreated or incompletely treated cases developed heart disease compared with only one out of the 15 effectively treated cases of sleep apnea.
The study authors say effective treatment of sleep apnea can reduce the extra heart-disease risk associated with the condition and should be considered even in milder cases where daytime sleepiness isn't reported.