MONDAY, Dec. 5, 2005 (HealthDay News) -- Even a moderate level of sleep apnea -- disordered breathing while sleeping -- can quadruple long-term stroke risk, a new study finds.
"Although our analysis cannot shed light on the pathway by which sleep-disordered breathing affects stroke risk, these novel findings add justification to considering the problem as a condition that either precedes or may contribute to the development of stroke," Dr. Douglas Bradley, of the Toronto General Hospital/University Health Network in Canada, said in a prepared statement.
The findings appear in the December issue of the American Journal of Respiratory and Critical Care Medicine.
People with sleep apnea repeatedly stop breathing long enough (10 seconds or more) to reduce the amount of oxygen in the blood and increase the amount of carbon dioxide. Moderate to severe sleep-disordered breathing is defined as 20 or more such events an hour.
The study included 1,475 people who were tested for sleep-disordered breathing and followed-up at four, eight, and 12 years. Seventy-six percent of the participants did not have sleep-disordered breathing, 17 percent had a mild form of the disorder and 7 percent had a moderate to severe problem.
Twenty-one of the people in the study suffered a first-ever stroke at an average age of 53.
"Our longitudinal analysis provides the first prospective evidence that sleep-disordered breathing after adjustment for age and sex is related to significantly increases odds of suffering a stroke over the next four years," Bradley said.
The American Lung Association has more about sleep-disordered breathing.