A scoping review of the evidence linking metabolic dysfunction-associated steatotic liver disease and hearing loss: mapping the liver-ear axis

Abstract

Fatty liver disease, currently termed metabolic dysfunction–associated steatotic liver disease (MASLD), is increasingly recognised as a systemic metabolic disorder with potential extrahepatic manifestations. However, the association between MASLD and hearing loss has not been systematically evaluated. We conducted a scoping review to evaluate the association between fatty liver disease and hearing impairment. Our review adhered to the PRISMA-ScR checklist and searched using keywords in four databases (PubMed, EMBASE, Scopus, and Cochrane). Studies assessing the association between MASLD and hearing outcomes were included. Risk of bias assessment was conducted using the Newcastle-Ottawa Scale and Joanna Briggs Institute checklist. Of 415 records identified, two studies involving 210,939 participants, including 192,467 individuals with fatty liver disease, met the inclusion criteria. Both studies demonstrated high methodological quality. Fatty liver disease was assessed using fatty liver index-based steatosis definitions, while hearing outcomes were evaluated using pure tone audiometry and validated ICD-based diagnoses of sudden sensorineural hearing loss. In both studies, individuals with fatty liver disease had a higher proportion of hearing impairment. Current evidence suggests a possible association between fatty liver disease and hearing impairment, supporting the concept of a metabolic–auditory link. Nevertheless, the evidence base remains limited, and further longitudinal studies using standardized MASLD definitions and objective hearing assessments are required to clarify causality and clinical implications.