The association between hearing loss in adults and cognitive outcomes: an umbrella review and meta-analysis.

PURPOSE: Hearing loss (HL) has been increasingly recognized as a potential risk factor for cognitive decline and dementia. However, findings from existing meta-analyses remain heterogeneous. This umbrella review aimed to comprehensively synthesize current meta-analytic evidence on the association between adult hearing loss and cognitive outcomes. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched from inception to 9 January 2026. Systematic reviews with meta-analyses examining the relationship between hearing loss and cognitive outcomes in adults were included. Methodological quality was assessed using AMSTAR-2. Evidence credibility was evaluated using the Ioannidis classification framework, and certainty of evidence was assessed using the GRADE approach. Overlap among primary studies across meta-analyses was quantified using the corrected covered area (CCA). RESULTS: Nine meta-analyses were included. Hearing loss was significantly associated with increased risk of cognitive impairment (OR = 1.34, 95% CI: 1.17-1.53) and dementia (OR = 1.43, 95% CI: 1.21-1.68). In older adults, the associations were slightly stronger. Hearing loss was also associated with higher risk of Alzheimer's disease (OR = 1.66, 95% CI: 1.33-2.07). Evidence credibility was classified as highly suggestive for cognitive impairment and dementia. CONCLUSION: Adult hearing loss is significantly associated with increased risks of cognitive impairment and dementia. These findings highlight the importance of hearing health in cognitive aging and support further prospective and interventional studies.