evaluation of the association between obstructive sleep apnea and hearing loss

background and objective : obstructive sleep apnea (osa) through hypoxia and reoxygenation periods leads to oxidative stress, endothelial dysfunction, and activation of inflammatory cycles, which eventually may cause disorder in vasa nervorum, and peripheral neuropathy in hearing pathway. in this study, we aimed to evaluate the effect of severe sleep apnea on hearing function. materials and methods : in this study, 91 individuals were evaluated and categorized in two groups of patients suffering from severe obstructive sleep apnea [apnea/hypopnea index (ahi) > 30], and controls (ahi < 5). pure tone audiometry (pta) was performed for all the subjects. results : mean hearing threshold at 250-8000 hz was 24.44 ± 6.80 db, and 15.75 ± 5.10 db in case and control groups, respectively (p < 0.01). evaluation of each frequency showed that hearing threshold was significantly higher at 4000 hz in the group with severe obstructive apnea. the only effective factor among all variances of sensorineural hearing loss in obstructive sleep apnea was the oxygen desaturation index, which predicted 18% of hearing loss variances. the frequency of hearing loss in patients with obstructive sleep apnea was higher than those without it. the severity of obstructive sleep apnea had significant relationship with hearing loss. conclusion : the frequency of hearing loss in patients with obstructive sleep apnea was estimated to be more than subjects without it. the severity of obstructive sleep apnea was associated with hearing loss. obstructive sleep apnea may be a risk factor for hearing loss due to hypoxia. thus, treatment of it may reduce risk of hearing loss. further studies are required to evaluate the influence of treatment of obstructive sleep apnea on hearing loss.