Observed Hearing Loss and Incident Dementia in a Multiethnic Cohort

ObjectivesTo determine whether observed hearing loss (OHL) is associated with incident dementia in a multiethnic population. DesignProspective epidemiological cohort study. SettingCommunity in northern Manhattan. ParticipantsParticipants in the Washington Heights-Inwood Columbia Aging Project, a longitudinal study on aging and dementia in an ethnically diverse community (n = 1,881). MeasurementsOHL was defined when the examiner observed it or according to self-reported hearing aid use. A consensus panel diagnosed dementia using standard research criteria. A Cox proportional hazards model was used to examine the relationship between OHL at baseline and risk of incident dementia (mean 7.3 4.4 years of longitudinal followup, range 0.9-20 years). ResultsOHL was associated with 1.69 (95% confidence interval (CI) = 1.3-2.3, P < .010) times the risk of incident dementia, adjusting for demographic characteristics, cardiovascular risk factors, apolipoprotein E4 genotype, and stroke. When stratified according to race, the association between OHL and incident dementia was high in all groups but was statistically significant only in blacks (hazard ratio = 2.62, 95% CI = 1.5-4.5, P < .010). ConclusionOHL was associated with greater risk of incident dementia in a multiethnic cohort. More study is needed to determine whether HL contributes to dementia and whether treating HL can reduce the risk of dementia.