Hearing Aids May Help Reduce Dementia Risk in Adults With Hearing Loss

Adults with hearing loss who did not use hearing aids, compared with those without hearing loss, had an increased risk of developing dementia.

Adults with hearing loss, compared with those without hearing loss, have a greater risk of developing all subtypes of dementia. Yet, there is no increased risk among adults with hearing loss who use hearing aids. These are the findings of a study published in the Lancet Public Health.

Hearing loss and dementia are among the most prevalent conditions experienced by older adults. Research has shown an association between these conditions and has reported hearing loss as a potential modifiable risk factor for dementia. 

Researchers conducted a population-based cohort study to assess the relationship between hearing aid use and the risk for dementia among middle-aged and older adults. 

The researchers took data from the UK biobank, a prospective population-based cohort with over 500,000 participants aged 40 to 69 years old between 2006 and 2010. All participants lived within 10 miles of 35 assessment centers and were invited to attend 1 center for baseline assessment. 

Public health strategies are necessary to raise awareness of hearing loss and the potential harm of untreated hearing impairment …

Participants answered the Touchscreen questionnaire regarding hearing loss and hearing aid use. The diagnosis of dementia was confirmed using inpatient records and death record data. 

The primary outcome was the incidence of all-cause dementia, including some dementia subtypes: Alzheimer disease, vascular dementia, and non-AD nonvascular dementia. 

After the exclusion of people with no hearing difficulties, 437,704 participants remained in the analysis. Study participants had an average baseline age of 56 years old (standard deviation [SD], 8 years); 53.7% were women; and 95.1% were White. 

Among the 111,822 participants with hearing loss, 13,092 (11.7%) used hearing aids. Hearing loss increased with age and was more common among men than women. 

The prevalence of hearing loss and hearing aid use was higher among participants with obesity, cardiovascular disease, loneliness, and depressed mood. 

Participants with hearing loss not using hearing aids, compared with people without hearing loss, showed an increased risk for all-cause dementia (hazard ratio [HR], 1.42; 95% CI, 1.28-1.57). However, there was no increased risk observed for participants with hearing loss who used hearing aids (HR, 1.04; 95% CI, 0.98-1.10). Similar findings were reported for each dementia subtype.  

The stratified analysis revealed that compared with men, women without hearing aid use have an increased risk for hearing loss associated with all-cause dementia (35.90% vs 25.93%), AD (28.06% vs 21.88%), vascular dementia (43.82% vs 31.03%), and non-AD non-vascular dementia (43.50% vs 25.93%).

The association between hearing aid use and dementia was alleviated when participants improved social isolation (1.52%), loneliness (2.28%), and depressed mood (7.14%).

Dementia was associated with high-risk populations, such as people with low income, previous disease, APOE e4 alleles, and smokers. 

Overall, this study shows that compared with people without hearing loss, those with hearing loss have a significantly greater risk for dementia and this association was observed among many dementia subtypes. 

The researchers acknowledged that “The underlying mechanisms linking hearing aid use and a reduced dementia risk remain unclear. Direct and indirect pathways might exist. Hearing aids might delay cognitive decline by preventing auditory deprivation.”

“Public health strategies are necessary to raise awareness of hearing loss and the potential harm of untreated hearing impairment, increase accessibility to hearing aids by reducing cost, encouraging screening, and delivering potential interventions such as fitting hearing aids,” they concluded.

Study limitations include misreporting, misclassification bias, lack of covariate randomization, and the potential inability to generalize results to deaf populations. 

References:

Jiang F, Mishra SR, Shrestha N, et al. Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort. Lancet Public Health. Published online April 13, 2023. doi:10.1016/S2468-2667(23)00048-8