Correlation between blood urea nitrogen level and cochlear outer hair cell function in non-dialysis chronic kidney disease patients

Background: Hearing loss due to impaired cochlear function, which results from increased blood urea nitrogen (BUN) level, is one of the important clinical problems in chronic kidney disease (CKD) patients with uremia. This study aims to determine correlation between blood urea nitrogen (BUN) levels and cochlear outer hair cell (OHC) dysfunction in non-dialysis stage 3-5 CKD patients so that the BUN levels may also be used to determine the presence of cochlear OHC dysfunction. Design and methods: An observational analytic study with a cross sectional design and consecutive sampling. This study was conducted from November 2019 to February 2020 at the Department of Internal Medicine, Soetomo Hospital, Surabaya, Indonesia, and Otorhinolaryngology-Head and Neck Surgery Department, Soetomo Hospital, Surabaya, Indonesia. Non-dialysis CKD patients who met the inclusion and exclusion criteria were subjected to a Distortion Product Otoacoustic Emissions (DPOAE) test to assess cochlear OHC function at the Otorhinolaryngology- Head and Neck Surgery, Soetomo Hospital, Surabaya. Results: Female patients were in larger number than male patients in a ratio of 1 : 2. Most of the patients were between 51-60 years of age. DPOAE distribution was refer in 25 patients (83.3%) and pass in 5 patients (16.7%). The highest pass was at 2000 Hz in 24 patients (80.0%), while the refer results were mostly at 12,000 Hz in 29 patients (96.7%). The highest average signal to noise ratio (SNR) was at 2000 Hz and 4000 Hz (12.77 dB and 11.13 dB), while the lowest at 11,000 Hz and 12,000 Hz (1.60 dB and 1.03 dB). Pearson’s correlation test on DPOAE results did not show a significant correlation (p>0.05) between BUN levels and impaired cochlear OHC function. Conclusions: There was no correlation between increased blood urea nitrogen levels and cochlear outer hair cell function disorders in non-dialysis patients with CKD stage 3-5.