Persons afflicted with severe breathing disorders during sleep face an increased risk of premature death, according to a new study.
The risk is most apparent in men 40-to-70 years old, said the study, published this week in the open access journal PLoS Medicine.
The signature symptom of sleep-disordered breathing -- experienced by one-in-four men and one-in-10 women -- is the temporary collapse of the upper airway.
Earlier research has shown that sleep apnea can lead to increased incidence of hypertension, heart failure and stroke.
It can also cause daytime sleepiness, impairing an individual's ability to drive a car or operate machinery.
But previous studies have not included enough participants to reveal whether other factors, such as age and sex, are linked to an increased risk of premature death.
In a study led by Naresh Punjabi of Johns Hopkins University in Baltimore, researchers measured the so-called apnea-hypopnea index (AHI) for over 6,000 men and women.
A person's breathing during sleep is severely disrupted when the AHI index -- which also monitors blood oxygen levels -- is 30 or above. Hypopnea is abnormally shallow breathing.
Regardless of age, sex, race, weight or smoking status, participants followed up for an average of eight years were one-and-a-half times more likely to die if they had an AHI of 30 or above at the outset of the study.
Men aged 40-to-70 in that category were twice as likely to die from any cause as men who did not suffer from sleep apnea.
Death from coronary heart disease in particular was linked to sleep disorders in men, but not in women.
Persons with milder sleep-breathing problems did not have a statistically increased risk of dying, according the study.
The researchers called for clinical trials to determine whether treating the condition can reduce premature deaths.