Relationship between hearing loss, cognitive impairment, and dementia; meta-analysis of cohort studies in which the exposure factor is hearing loss measured by audiometry.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational cohort studies
PubMed 41806683 · doi:10.1016/j.amjoto.2026.104799
What was done
Meta-analysis of cohort studies published between 2019 and 2023 evaluating the association between hearing loss and cognitive decline or incident dementia. Exposure was strictly required to be hearing loss assessed via pure-tone audiometry, and outcomes were assessed via validated cognitive scales or clinical onset of dementia. From 5,349 initial records, 11 cohort studies met inclusion criteria for the systematic review, and 8 were included in the quantitative meta-analysis.
What was found
In studies where the outcome was incident dementia expressed as a hazard ratio, audiometrically measured hearing loss was significantly associated with increased dementia risk (HR 1.32, 95% CI 1.30–1.34) with low heterogeneity and low risk of publication bias. In studies where cognitive decline was evaluated as a continuous outcome using linear regression (beta coefficients), no statistically significant relationship was observed.
Why it matters
This review clarifies that objectively confirmed peripheral hearing loss is consistently linked to a higher risk of clinical dementia diagnosis in recent cohort data, rather than relying on self-reported hearing status. It also notes that continuous cognitive score decline did not show the same statistical relationship.
Limits
The search window was restricted to 2019–2023, potentially excluding earlier foundational cohorts. Because all included designs are observational, residual confounding and reverse causation cannot be ruled out. The abstract does not report total participant counts, follow-up durations, specific dementia subtypes, or adjustments for key covariates. Central hearing loss and auditory processing deficits were not evaluated.