Two studies in the August 1 issue of the journal Sleep come to the same conclusion: obstructive sleep apnea can be deadly.

 

One population study involved 1,522 adults in Wisconsin. They were tested for sleep apnea during an overnight sleep study at a university research center. Then they were followed up for a period of 18 years. 

 

Results show that people with sleep apnea have a much higher risk of death than people without sleep apnea. The risk is greater for people whose sleep apnea is more severe. The risk of death also increases when sleep apnea is untreated.

 

“People with untreated, severe sleep apnea had four times the risk of all-cause mortality, and five times the risk of cardiovascular death,” said lead author Terry Young, PhD. She is a professor at the University of Wisconsin-Madison. 

 

About 19 percent of adults with severe sleep apnea died over the course of the study. Only about four percent of people who had no sleep apnea died during the same time period. About 42 percent of deaths in people with severe sleep apnea were related to heart disease or stroke. 

 

According to the American Academy of Sleep Medicine, obstructive sleep apnea involves a decrease or complete halt in airflow despite an ongoing effort to breathe. It occurs when the muscles relax during sleep. As a result soft tissue in the back of the throat collapses and blocks the upper airway.

 

Young said that these repeated pauses in breathing cause “compound stress.” Blood pressure rises drastically. Irregular heart rhythms occur. Oxygen levels drop, and sleep is fragmented. The pauses can occur 30 or more times an hour, all night long. Over a lifetime, this stress can take a severe toll on the body.

 

Young estimated that about 10 percent of adults in the U.S. have a significant problem with sleep apnea. She fears that the rising rate of obesity will make sleep apnea even more common. Obesity is one of the key risk factors for sleep apnea.

 

Nathaniel Marshall, PhD, agrees that sleep apnea should be taken seriously. He is a postdoctoral fellow at the Woolcock Institute of Medical Research in Sydney, Australia. Marshall and his colleagues found similar results in a community study of 380 adults.

 

“Our findings, along with those from the Wisconsin Cohort, remove any reasonable doubt that sleep apnea is a fatal disease,” he said.

 

Adults in Marshall’s study were tested for sleep apnea using a portable home-monitoring device for one night. Then they were followed up for a period of 14 years.

 

About 33 percent of study subjects with moderate to severe sleep apnea died during the follow-up period. Only 7.7 percent of people who had no sleep apnea when the study began died over the course of the study. Overall, people with moderate to severe OSA had six times the risk of death.

 

“In our particular study a six-fold increase means that having significant sleep apnea at age 40 gives you about the same mortality risk as somebody aged 57 who doesn't have sleep apnea,” noted Marshall. 

 

Young’s study did provide some good news about treating sleep apnea with continuous positive airway pressure (CPAP) therapy. Results suggest that regular use of CPAP may protect people with sleep apnea against heart-related death.

 

“Our findings suggest - but cannot prove - that people diagnosed with sleep apnea should be treated,” said Young. “And if CPAP is the prescribed treatment, regular use may prevent premature death.”

 

According to the American Academy of Sleep Medicine, CPAP therapy is the most common treatment for OSA. It provides a steady stream of air through a mask that is worn during sleep. This airflow keeps the airway open to prevent pauses in breathing. It also restores normal oxygen levels.

 

Young noted that most people with sleep apnea have not been treated. She said that it is urgent to get medical help if you suspect that you may have sleep apnea.

 

“People who think they have sleep apnea due to being told they snore and stop breathing should seek evaluation,” she said. “People with mild sleep apnea should be cautious about progression of their sleep apnea due to weight gain.”

 

Get expert help for sleep apnea at a sleep disorders center that is accredited by the American Academy of Sleep Medicine. You can find an AASM-accredited sleep center near you at www.sleepcenters.org.