Obstructive Sleep Apnoea Syndrome and Association of AHI Scores with Sensorineural Hearing Loss: An Early Predictor

Obstructive sleep apnoea syndrome (OSAS) is a condition that is characterised by frequent apnoea and hypopnoea attacks occurring during sleep. The blood supply to cochlea and acoustic nerves is from terminal arteries, thereby making them susceptible to hypoxia. To compare the audiological profiles in patients with OSAS according to Apnoea Hypopnoea index (AHI) score. Descriptive study was conducted in 32 patients diagnosed to have OSAS in a tertiary referral centre over two year period. The study group was divided into mild, moderate, severe OSAS based on AHI score. The hearing evaluation was done using pure tone audiogram (PTA) and distortion product otoacoustic emission test (DPOAE). Moderate and severe OSAS participants had elevated thresholds at higher frequencies in PTA (4 kHz, 8 kHz), although this was not statistically significant. We also noticed, absent DPOAE responses at higher frequencies (4 k, 6 k, 8 k), with increase in the severity of OSAS at higher frequency, which was statistically significant (p value < 0.05). This study revealed elevated hearing thresholds at higher frequencies (4 kHz, 8 kHz) in PTA and DPOEA with an increase in the severity of OSAS. All OSAS patients, especially with AHI > 30 should be regularly screened for hearing loss.