Major study links disordered breathing to deadly cardiovascular complications
TUESDAY, Aug. 18 (HealthDay News) -- The classic manifestations of sleep apnea -- loud snoring, interrupted breathing and sleep disruption -- nearly double the risk for chronic disease and premature death among middle-aged and elderly men, according to major new research.
Even patients with moderate sleep apnea face an increased death risk, as much as 17 percent, compared with those who do not have sleep-disordered breathing problems, the decade-long U.S. study finds.
"The primary finding of our study is that sleep apnea can increase the risk of death by about 40 percent, even after other factors have been accounted for," said study lead author Dr. Naresh Punjabi, an associate professor of medicine at the Johns Hopkins University School of Medicine in Baltimore.
"Our study also shows that it is the decrease in oxygen levels during sleep from sleep apnea that explains the increased risk of death," added Punjabi. Men with sleep apnea between the ages of 40 and 70 are particularly at risk of death from any source, but especially from cardiovascular disease, the researchers found.
Punjabi and his colleagues published their findings in the online Aug. 18 issue of the journal PLoS Medicine. The research effort is the largest ever to explore associations between sleep disturbances and illness, they said.
Sleep apnea is a common, chronic condition that affects about one in four men and about one in 10 women, the authors note. Left untreated, it can lead to excessive sleepiness, difficulties with daytime alertness and an increased risk for driving accidents.
For their study, the research team at Johns Hopkins Bayview Medical Center focused on more than 6,400 men and women between 40 and 70 years old who had mild to severe sleep apnea or had no such sleeping difficulties. Many participants described themselves as "snorers," a prime feature of sleep apnea.
During home monitoring of sleep patterns, the team amassed almost 10,000 in-depth recordings of breathing patterns, heart rhythms and brain activity during sleep.
After determining that about half the patients had moderate to severe sleep apnea, the researchers went on to track the incidence of sickness or death from high blood pressure, heart disease and/or stroke.
Over a tracking period of a little more than eight years, on average, the research team found that 587 men and 460 women died during the study.
Stacking the death tallies against the sleep pattern recordings, the team found that experiencing just 11 minutes of severe sleep apnea -- during which blood oxygen levels dipped to below 90 percent of normal -- appeared to roughly double the risk of death among men.
The small number of women with severe sleep apnea who died during the study ruled out similar conclusions about women.
Nonetheless, Punjabi and his colleagues stressed that the findings were alarming enough to warrant diligent physician attention to patient sleeping habits, in order to intervene quickly when appropriate.
"With such mounting evidence indicating the range of clinical effects of sleep apnea, awareness amongst health care professionals and the general community needs to increase," Punjabi said.
Losing weight sometimes reduces sleep apnea, and some sufferers get relief using a device that keeps them from rolling on their backs while they sleep. For serious cases, a current treatment is the "continuous positive airway pressure" (CPAP) device, which functions as a kind of oxygen mask worn over the nose to help force air into nasal passageways and prevent airways from collapsing.
People with clinical symptoms of sleep apnea, which include loud snoring, sleepiness during the day and fatigue, should discuss their symptoms with a physician, Punjabi advised. "Effective therapy for sleep apnea can improve such symptoms and lead to a better quality of life," he said.
Jim Cappuccino, a 49-year-old sleep apnea patient living in the Baltimore suburbs who was part of Punjabi's study, agreed.
Cappuccino, the owner of a surgical equipment and medical device sales company, knew he had high blood pressure, high cholesterol and type 2 diabetes before enrolling in the study.
Although he can trace the onset of sleep apnea difficulties, such as disruptive snoring and breathing pauses, back to his mid-30's, it was only when he enrolled in the study that he was finally diagnosed with sleep apnea, he said.
"When you're in that career mode, and you're on the go-go-go, you put your health issues on the back burner," he said. "But as I got older, I realized that this is probably something that I should have addressed years ago. I was shocked by the correlation between sleep apnea and heart disease and diabetes, and actually even death, but getting tested and diagnosed and treated has made all the difference. It's actually allowed me to wake up not feeling tired, which hasn't been the norm for me for a few years."
"So the only thing I can say," Cappucino added, "is people who feel that they are having trouble should get tested, because sleep apnea is going to deteriorate your system and lead to many other health problems."
Similar findings that linked severe sleep apnea with a greater risk of dying were reported last year in studies out of Australia and the University of Wisconsin.
For additional information and resources on sleep apnea, visit the American Sleep Apnea Association.
SOURCES: Naresh Punjabi, M.D., Ph.D., associate professor of medicine, Johns Hopkins University School of Medicine; Jim Cappuccino, sleep apnea patient and study participant, Parkville, Md.; Aug. 18, 2009, online, PLoS Medicine
All rights reserved