A Japanese woman sleeps.

Persons afflicted with severe breathing disorders during sleep face an increased risk of premature death, according to a new study.

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. This leads to brief interruptions of breathing known as sleep apnea that can last from a few seconds to more than a minute.

Earlier research has shown that sleep apnea can lead to increased incidence of hypertension, heart failure and stroke.

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 40-70 in that category were twice as likely to die from any cause as men who did not suffer from sleep apnea.

The researchers called for clinical trials to determine whether treating the condition can reduce premature deaths.

Source: AFP