Moderate to severe obstructive sleep apnea—a narrowing of the upper airway that can hinder breathing during sleep—might increase the risk of death in middle-aged adults, according to a study supported by the National Heart, Lung and Blood Institute (NHLBI) and reported on by ScienceDaily.

The disorder also causes loud snoring and daytime fatigue.

More than 6,000 men and women ages 40 and older (both sufferers and non-sufferers of sleep apnea) participated in the Sleep Heart Healthy Study (SHHS).

Researchers found that, after an average of eight years, the participants who had sleep apnea had a 40 percent increased risk of death (from any cause) compared with those who did not have the condition.

Study results also showed that the risk of mortality (from any cause) was more apparent in men with severe sleep apnea.

Other studies have linked untreated sleep apnea to a number of conditions, such as obesity, diabetes, high blood pressure, heart disease, heart failure and stroke.

More than 12 million Americans are believed to have undiagnosed and untreated sleep apnea.

Visit the American Lung Association at to find out the best way to seek help.

Read RH’s “Snoring Can Be a Serious Health Issue” for more information about sleep apnea.