P021 Does Obstructive Sleep Apnea (OSA) lead to impairment within the cochlea?

INTRODUCTION: The cessation of breathing with OSA is linked to the continuous decrease in oxygen saturation throughout the night which could impact the inner ear as it is sensitive to hypoxic changes. Inner ear hair cells response from the cochlea is measured through Transient Otoacoustic Emission (TEOAEs). This study aimed to evaluate TEOAEs in suspected OSA patients and its correlation with oxygen saturation. METHODS: TEOAEs were measured before sleep and in the morning in suspected OSA patients and healthy participants. The following frequencies were measured: 1000Hz, 1500Hz, 2000Hz, 3000Hz and 4000Hz. Polysomnography with oxygen saturation was completed overnight. Preliminary analysis was completed on 11 no OSA, 22 mild OSA, 13 moderate OSA and 27 severe OSA patients. RESULTS: One-way ANOVA with Tukey post-hoc analysis revealed a difference between severe vs mild with average TEOAE only (p = 0.04). A moderate correlation was found between average TEOAE and minimum O2 saturation, rs (72) = 0.444, p< 0.0001) through Spearman’s rank-order correlation. As middle ear function can impact TEOAE results, regression analysis revealed an association between a decrease in TEOAE and lowered minimum O2 saturation (F (1,63) = 8.951, p = 0.004, partial n2 = 0.124) when middle ear pressure was controlled. DISCUSSION: Oxygen desaturation with OSA is associated with a decrease in inner ear hair cells response, which was independent from middle ear function. Despite this association, a difference in TEOAE was only found between severe vs mild, which could be due to the current sample size of the preliminary data.