Sleep apnea, a symptom of which is snoring, is related to hearing loss in both high and low frequencies, according to a study that was presented at the 2014 American Thoracic Society International Conference.
It was held on May 16-21 in San Diego.
Sleep apnea is a disorder of breathing during sleep. Its symptom is snoring, although not every snorer suffers from sleep apnea. This ailment is diagnosed by the occurrence of at least 5-15 breathing stops per hour during sleep, with the duration of these pauses being about 10 seconds.
Frequent respiratory arrests cause tissue hypoxia, including the heart muscle and nervous tissue. Therefore, people suffering from apnea experience fatigue, excessive sleepiness, irritability and headaches during the day. Sleep apnea has also been linked to a higher risk of cardiovascular disease such as high blood pressure, arrhythmias, heart attack, stroke, sudden cardiac death and heart failure, and metabolic disorders such as diabetes.
The most common type of sleep apnea is called sleep apnea. obstructive apnea, which is associated with the relaxation of the muscles in the throat and the collapse of its soft structures during sleep. This leads to blockage of the flow of air to the lungs. The risk factors for this type of apnea include overweight and obesity, male gender, and middle or older age.
Scientists led by Amit Chopra from Albany Medical Center in New York conducted research among nearly 14 thousand. people belonging to the Latin American community, aged 18-74. All of them underwent sleep apnea tests and audiometric tests that test their hearing.
The severity of the apnea was measured by the number of apnea and shortness of breath during one hour of sleep (known as the AHI index). Almost 10 percent respondents had at least moderate sleep apnea (AHI equal to or greater than 15).
Hearing loss in the high-frequency range was assumed to be an average hearing threshold of more than 25 decibels (dB) in each ear at sounds with a frequency of 2. hertz (Hz), 3 Hz, 4k Hz, 6K Hz and 8k Hz. On the other hand, hearing loss in the range of low frequencies was diagnosed in people whose hearing threshold was higher than 25 dB in each ear at sounds with a frequency of 0,5 thousand. Hz and 1 thous. Hz.
Overall, hearing loss was found more frequently among those who snore or had sleep apnea and had a higher body mass index (BMI). As calculated by the authors of the study, sleep apnea increased by 31 percent. risk of hearing loss in the high frequency range, by 90% – in the low frequency range and by 38% in the high and low frequency range. The analysis took into account gender, age, exposure to noise, as well as previous hearing impairment, also conductive hearing loss (localized in the middle ear conductive apparatus) and other factors. Higher AHI was more strongly associated with hearing loss in the high frequency range.
One limitation of the study, the researchers noted, was that it did not take into account the impact of sleep apnea treatment on the final results. However, participants were rarely treated for this condition.
“Sleep apnea patients are at risk of a variety of comorbidities including heart disease and diabetes, and our results show that sleep apnea is also associated with an increased risk of hearing impairment,” commented Dr. Chopra.
As he emphasized, the mechanism underlying this relationship requires further research. Potentially, sleep apnea can adversely affect the blood supply to the cochlea in the inner ear as it promotes inflammation and remodeling of blood vessels; Noise from snoring may also contribute to hearing loss, the authors speculate. The average intensity of sounds made by a snorer is about 50 dB or even more, while the noise standards are set at less than 30 dB. (PAP)