A new study, published in the Aug. 1 issue of Sleep, linked the interrupted nighttime breathing of sleep to an increased risk of death. People with obstructive sleep apnea are up to three times more likely to die too early, and that risk rises if the sleep disorder isn’t medically treated.

In the study, conducted by epidemiologist Terry Young and her co-workers at the University of Wisconsin-Madison, data from 1,522 participants was analyzed. The 18-year follow-up involved men and women who were between the ages of 30 and 60 when the study was initiated.

The report disclosed that adults who suffered from sleep-related disorders at the beginning of the study were up to three times more likely to pass away from any cause, in contrast with adults who didn’t have sleep-disordered breathing. Researchers attributed the risk of premature death to severe obstructive sleep apnea, refusing to relate it to age, gender, body weight or cardiovascular health status.

The team of researchers discovered that 63 of the participants, or 4 percent, had moderate to severe apnea, 20 percent had mild apnea, and the rest had none.

Sleep apnea is a widespread problem. People suffering from apnea have pauses in breathing or shallow breaths while sleeping. There is no movement of the muscles of respiration and the volume of the lungs initially remains the same. According to the National Heart, Lung and Blood Institute, 12 million to 18 million people in the U.S. have moderate to severe apnea.