Moderate CKD is associated with hearing loss, according to Australian researchers. A team led by Paul Mitchell, MD, PhD, of the Centre for Vision Research at the University of Sydney, Westmead, New South Wales, and colleagues conducted a cross-sectional population-based study involving 2,564 participants.
All subjects underwent audiometric testing and measurement of serum creatinine. Investigators asked hearing-related questions that examined family history of hearing loss, risk factors for ear disease, past medical or surgical treatment of otologic conditions, and diseases associated with hearing loss.
A total of 513 subjects (20%) had moderate CKD, defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2. Of these, 279 (54.4%) had measured hearing loss compared with 581 (28.3%) with an eGFR of 60 or higher, the researchers reported online in the American Journal of Kidney Diseases. After adjusting for age, gender, diabetes, hypertension, stroke history, smoking, noise exposure, and education, moderate CKD was independently associated with a 43% increased risk of hearing loss.
In addition, subjects with an eGFR below 45 had the highest prevalence (73%) of hearing loss and those with an eGFR of 90 or higher (reference group) had the lowest prevalence (19%). Compared with the reference group, individuals with an eGFR below 45 had a 2.4 times increased risk of hearing loss after adjusting for multiple confounders, according to the investigators.
The association between moderate CKD and hearing loss remained significant after excluding patients who were treated with furosemide, an ototoxic medication.
“Hearing loss is commonly linked to syndromal kidney disease. However, this study suggests a strong tie to CKD in general,” said study author David C. Harris, Associate Dean of Sydney Medical School-Westmead at the University of Sydney. “The link can be explained by structural and functional similarities between tissues in the inner ear and in the kidney. Additionally, toxins that accumulate in kidney failure can damage nerves, including those in the inner ear.”
Another reason for this connection, he said, is that kidney disease and hearing loss share common risk factors, including diabetes, high blood pressure, and advanced age, factors that he and his colleagues adjusted for in their study.
The authors concluded that their data confirm those from previous studies showing a link between CKD and hearing loss and “suggest that earlier clinical hearing assessment with appropriate audiologic testing and interventions such as the appropriate fitting of hearing aids could preserve hearing function in patients with CKD.”