The association between reduced kidney function and hearing loss: a cross-sectional study.

Background: The relationship between kidney function and hearing loss has long been recognized, but evidence of this association mostly comes from small observational studies or other populations. The aim of this study is to explore the association between reduced kidney function and hearing loss in a large population-based study among the middle-aged and elderly Chinese.

Methods: Data collected from the Chinese Health and Retirement Longitudinal Study (CHARLS) in 2015 were used for analysis. A cross-sectional study was conducted among 12,508 participants aged 45 years and older. Hearing loss, the outcome of this study, was defined according to interviewees' responses to three survey questions related to hearing in the CHARLS. Estimated glomerular filtration rate (eGFR) was employed to assess kidney function, and participants were classified into three categories based on eGFR: ≥90, 60-89 and < 60 mL/min/1.73 m. Multivariable logistic regression was employed to adjust for potential confounders, including demographics, health-related behaviors, and cardiovascular risk factors.

Results: The overall prevalence of self-reported hearing loss in the study population was 23.6%. Compared with participants with eGFR ≥90 mL/min/1.73 m, participants with eGFR of 60-89 mL/min/1.73 m (odds ratio [OR]: 1.11, 95% confidence interval [CI]: 1.00-1.23) and eGFR < 60 mL/min/1.73 m (OR: 1.25, 95% CI: 1.04-1.49) showed increased risk of hearing loss after adjusting for potential confounders.

Conclusions: Reduced kidney function is independently associated with hearing loss. Testing for hearing should be included in the integrated management of patients with chronic kidney disease.