Hearing & Cognition-Article: Adult Onset HL and Incident Cognitive Impairment and Dementia (Yu et al 2024)

Article: Adult Onset HL and Incident Cognitive Impairment and Dementia (Yu et al 2024)

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This systematic review and meta-analysis examined whether adult-onset hearing loss is associated with later cognitive impairment and dementia. It included 50 cohort studies involving 1,548,754 participants. Eligible studies measured hearing at baseline, excluded dementia at baseline, followed participants for at least two years, and reported adjusted associations with subsequent cognitive outcomes.<br /><br />Hearing loss was associated with higher risks of dementia (hazard ratio [HR] 1.35), mild cognitive impairment (HR 1.29), cognitive decline (HR 1.29), and Alzheimer’s disease dementia (HR 1.56). The association with vascular dementia was not statistically significant, although few studies assessed this outcome. Greater hearing loss also corresponded to greater dementia risk: each 10-decibel worsening in hearing was associated with a 16% increase in risk. The association did not significantly differ according to factors such as age, follow-up duration, hearing-assessment method, or adjustment for cardiovascular risks.<br /><br />Overall, findings across diverse studies support hearing loss as a consistent risk marker for future cognitive decline and dementia. However, observational evidence cannot establish that hearing loss directly causes these outcomes; residual confounding and dementia’s long preclinical phase may contribute. Whether treating hearing loss prevents or delays dementia remains uncertain. A large trial found no cognitive benefit across its full sample, although a higher-risk subgroup showed slower decline. Further trials are needed to clarify the potential preventive effects of hearing aids.

Keywords

hearing loss

cognitive impairment

dementia

systematic review

meta-analysis

Alzheimer’s disease

mild cognitive impairment

cognitive decline

hazard ratio

hearing aids

Alzheimer's disease

cohort studies