Sleep-disordered breathing (also known as sleep apnea) is associated with an increased risk of death, according to new results from the Wisconsin Sleep Cohort, an 18-year observational study supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health.
Researchers found that adults (ages 30 to 60) with sleep-disordered breathing at the start of the study were two to three times more likely to die from any cause compared to those who did not have sleep-disordered breathing. The risk of death was linked to the severity of sleep-disordered breathing and was not attributable to age, gender, body mass index (an indicator of overweight or obesity), or cardiovascular health status.
"Sleep-Disordered Breathing and Mortality: Eighteen-Year Follow-Up of the Wisconsin Sleep Cohort," is published August 1 in the journal Sleep.
Researchers followed 1522 generally healthy men and women for an average of 13.8 years after testing them for sleep-disordered breathing using a standard overnight sleep test. Participants with severe sleep-disordered breathing were three times more likely to die during the study than those without breathing problems during sleep. Those who were not treated were at even greater risk. Participants with untreated severe sleep-disordered breathing were four times more likely to die from any cause and five times more likely to die from cardiovascular conditions.
The Wisconsin Sleep Cohort is the most comprehensive assessment yet of mortality risks associated with sleep-disordered breathing and the first to study a randomly selected population of adults in the United States. The findings suggest that the treatment of severe sleep-disordered breathing may be protective, especially against cardiovascular deaths. Further studies are needed to determine whether the findings are applicable across the United States, and how treatment may improve survival, quality of life, and the overall health status of affected individuals.
Michael J. Twery, PhD, director of the NHLBI National Center on Sleep Disorders Research, is available to comment on these findings, as well as on associated health risks of sleep-disordered breathing, and the importance of diagnosing and treating the condition.