A recent cross-sectional study found a significant association between chronic kidney disease (CKD), hearing loss, and tinnitus.
In the study, published in Frontiers in Medicine, investigators from the Guangzhou University of Chinese Medicine used 2015 to 2018 National Health and Nutrition Examination Survey (NHANES) data to analyze the outcomes of 5,131 patients aged 20 years and older. They conducted multivariate logistic regression analyses and subgroup analysis to better understand the relationship between CKD, hearing loss, and tinnitus.
CKD was characterized by an estimated glomerular filtration rate (eGFR) lower than 59 mL/min/1.73m2 or an albumin-to-creatinine ratio (ACR) higher than 30 mg/g. Hearing loss was self-reported by the patients, and tinnitus was defined as ringing or buzzing in the ears lasting 5 minutes or more within the past 12 months.
Among the patients, 19.3% (n = 989) of them had CKD. The mean age of the CKD group was 62.9 ± 16.0 years compared with 46.6 ± 16.5 years in the non-CKD group. The investigators showed that the patients with CKD were more likely to have concurrent hearing loss than those without CKD (95% confidence interval [CI] = 1.1–1.55, P = .002), after adjusting for potential confounders such as age, sex, race, education level, marital status, poverty income ratio, body mass index (BMI), smoking, depression, and cardiovascular disease.
No significant association was found between tinnitus and CKD in the overall population. However, subgroup analyses revealed that tinnitus was significantly associated with CKD in specific subgroups—including those aged 45 years or older (multivariate odds ratio [OR= = 1.29, 95% CI = 1.03–1.6), females (multivariate OR = 1.59, 95% CI = 1.17–2.16), nonsmokers (multivariate OR = 1.84, 95% CI = 1.34–2.51), and those with a BMI of 25 kg/m2 or greater (multivariate OR = 1.47, 95% CI = 1.17–1.85).
The investigators noted that the kidney and cochlea share anatomical and physiological similarities, which might help explain the observed associations. They highlighted that both organs have similar antigenic properties in the glomerular basement membrane and cochlear vascular stripe. Additionally, both rely on Na+, K+- ATPase activity, which plays a key role in maintaining cation gradients.
The findings suggested that early clinical manifestations of CKD in patients may not be significant. Therefore, paying attention to hearing changes could prompt patients to seek clinical consultation. They recommended early hearing assessment and testing for patients with CKD, with timely feedback to physicians.
The study's limitations included its cross-sectional design, which precluded causal inferences, and the lack of weighting in the analysis. The investigators called for further extensive prospective studies to establish a causal relationship between CKD and auditory dysfunction as well as to explore the detailed relationships between kidney function and hearing health.
The investigators concluded that there may be a significant association between CKD, hearing loss, and tinnitus in specific subpopulations. They hypothesized that patients with CKD may be at a higher risk for hearing loss and tinnitus; however, the results did not establish a causal relationship. They hope their findings can lead to the development of novel treatments to improve patient care.
The authors declared having no competing interests.