Sleep Apnea May Snuff Out Some Sound

Sleep apnea linked to hearing loss of both high and low frequencies

(RxWiki News) Sleep apnea has been linked to problems with blood flow. As healthy blood flow is crucial to many functions of the body, including the five senses, it's possible that sleep apnea could play a part in damage to our senses.

A recent study found that people with sleep apnea had an increased risk of developing hearing loss of both low and high frequencies.

The researchers discovered that factors such as snoring, typical outside noise exposure and history of hearing loss did not affect the risk of hearing loss.

"Get your hearing checked if you have sleep apnea."

The lead author of this study was Amit Chopra, MD, from the Albany Medical Center in Albany, New York.

The study included 13,967 participants from the Hispanic Community Health Study/Study of Latinos — a population-based study group of Hispanics and Latinos from four different sites in the United States.

A total of 8,399 (52 percent) of the participants were women, and the average age of all the participants was 41 years old.

At the beginning of this study by Dr. Chopra and team, the participants completed a sleep apnea test at home. They also went through audiometric testing (tests of ability to hear sounds) at the study site.

Sleep apnea is a condition in which a person has one or more pauses in breathing or shallow breathing while they sleep. The participants in this study were diagnosed with the condition according to the apnea-hypopnea index (AHI), which indicates sleep apnea severity based on the number of apneas (breathing completely stops) and hypopneas (breathing partially stops) per hour of sleep.

Sleep apnea cases were defined as having an AHI of 15 or more events per hour.

The researchers considered a participant to have high frequency hearing loss if they could not hear sounds in either ear that were lower than 25 decibels at 2,000, 3,000, 4,000, 6,000 and 8,000 Hertz. Low frequency hearing loss was defined as the inability to hear sounds in either ear that were lower than 25 decibels at 500 and 1,000 Hertz.

If a participant had both high frequency and low frequency hearing loss, they were considered to have combined high-low frequency hearing loss.

Frequency is a measure of sound waves that determines the pitch. The typical human hearing range is 20 to 20,000 Hertz. Decibels measure the loudness of a sound, and the typical human hearing ranges from 0 to 20 decibels at all frequencies.

The findings showed that 1,576 (10 percent) of the participants had sleep apnea, and 4,855 (29 percent) of the participants had hearing loss.

The researchers found that 3,248 (19 percent) of the participants had hearing loss at high frequencies, 217 (2 percent) had hearing loss at low frequencies, and 1,390 (8 percent) had hearing loss at both high and low frequencies.

There was a higher prevalence of hearing loss among the participants with Cuban and Puerto Rican backgrounds, those with a high body mass index (height to weight ratio), those who snored, and those who had sleep apnea.

Sleep apnea was associated with a 31 percent increase in high frequency hearing loss and 90 percent increase in low frequency hearing loss.

Sleep apnea was also associated with 38 percent increase in hearing loss at both high and low frequencies.

The researchers discovered that sleep apnea was independently associated with hearing loss after adjusting for age, sex, background, history of hearing loss, exposure to outside noises, conductive hearing loss (sound can’t travel correctly in the ear because of a physical problem), high blood pressure, diabetes, high blood fat level, cigarette and alcohol use, and history of snoring.

Dr. Chopra concluded that sleep apnea patients may be at increased risk for hearing loss. Further research is needed on the relationship between sleep apnea and the inflammation of the blood vessels.

The authors noted that their study was limited because they did not know the impact of potential sleep apnea treatments on the findings. However, treatment was rare in the study group.

This study was presented on May 20 at the 2014 American Thoracic Society International Conference.

Review Date: 
May 20, 2014