By Barbara Bronson Gray
The study found that sleep apnea was associated with hearing impairment at both high and low frequencies. That finding held true even after the researchers adjusted the data for other possible causes of hearing loss.
These findings give further support to the idea that sleep apnea likely doesn't occur in isolation. Instead, it may be a sign of other underlying health conditions, the researchers said.
"Sleep apnea is more of a systemic and chronic disease than just something that happens when you're sleeping," said one of the study's authors, Dr. Neomi Shah, an associate director of the pulmonary sleep lab at Montefiore Medical Center in New York City.
"It probably affects multiple different organs, so I would probably urge we start thinking about sleep apnea as more like a chronic disease with vascular and inflammatory issues," Shah added.
Sleep apnea is a common disorder that affects about 18 million Americans, according to the National Sleep Foundation. Typically signaled by snoring with periodic gasping or "snorting" noises, sleep apnea interrupts sleep and can cause excessive daytime fatigue and other symptoms. The condition also has been associated with generalized inflammation, cardiovascular and endocrine problems.
What might the connection be between sleep apnea and hearing loss? It might be a combination of factors that cause inflammation and abnormal functioning in the blood vessels, according to Shah. "The ear is prone to this kind of injury," explained Shah.
The study tapped data from almost 14,000 U.S. participants in the Hispanic Community Health Study/Study of Latinos. About 53 percent were women and on average the subjects were 41 years old. All completed in-home sleep studies and audiometric (hearing) testing.
About 10 percent of the study volunteers had sleep apnea. Around 30 percent had some form of hearing impairment, according to the study.
The researchers took into account age, gender, Hispanic/Latino backgrounds and health-related issues such as high blood pressure, diabetes, fat levels in the blood, cigarette and alcohol use, history of hearing loss or snoring, and noise exposure.