Elucidating the relationship between hearing loss, social isolation, and dementia: data from the National Health and Aging Trends Study

OBJECTIVES: Dementia is a growing public health challenge affecting millions. Hearing loss is a potentially modifiable risk factor, though its precise pathway to dementia remains unclear. Social isolation may influence this relationship. This study examines the association between hearing loss and dementia, assessing for a moderating role of social isolation. METHODS: We analyzed data from the National Health and Aging Trends Study (NHATS), including individuals aged 65+ without baseline dementia. Hearing loss was assessed via pure tone audiometry, categorized as normal, mild, or moderate-severe. Social isolation was evaluated using a validated composite measure derived from NHATS items. The NHATS dementia classification algorithm was used. Stratified multivariable logistic regression models were used to evaluate the relationship between hearing loss and dementia and to examine the moderating effect of social isolation. RESULTS: Moderate-severe hearing loss significantly increased dementia odds (odds ratios [OR] = 1.91, 95% confidence intervals [95% CI]: 1.11-3.29)-with attenuation observed among hearing aid users (OR = 1.84, 95% CI: 0.97-3.49). Individuals with hearing impairment demonstrated higher rates of social isolation (p < .001), which independently correlated with increased dementia incidence (p = .001). Stratified analyses revealed a significant association between moderate-severe hearing loss and odds of dementia among non-socially isolated individuals (OR = 2.29, 95% CI: 1.18-4.43), but not among socially isolated individuals (OR = 1.25, 95% CI: 0.39-4.04). DISCUSSION: Moderate-severe hearing loss is associated with increased dementia risk-a relationship that appears moderated by social isolation status. This data may provide preliminary insights into potentially mediating effects. Further longitudinal research is needed to clarify this pathway and inform dementia prevention strategies.