Treating hearing loss may lower dementia risk: study

Findings from a new study suggest older adults with severe hearing loss are more likely to have dementia, whilst the likelihood decreases in those who use hearing aids compared to non-users.

Researchers at the Johns Hopkins Bloomberg School of Public Health studied a sample of more than 2400 older adults and published their findings in the Journal of the American Medical Association. The findings are consistent with previous studies which have demonstrated a correlation between hearing loss, treatment and dementia.

“This study refines what we’ve observed about the link between hearing loss and dementia, and builds support for public health action to improve hearing care access,” said lead author Alison Huang, PhD, MPH, a senior research associate in the Bloomberg School’s Department of Epidemiology and at the Cochlear Center for Hearing and Public Health, also at the Bloomberg School.

In Australia, hearing loss is a critical public health issue; the Department of Health reports that about 3.6 million people have some level of hearing loss. The Hearing Care Industry Association states, “One in six Australians currently suffer from hearing loss. This number is expected to rise to one in four by 2050, thanks to an aging population and an increasing amount of people being exposed to dangerously loud noise.”

Of the 2413 individuals in the study, approximately half were aged 80 or older and demonstrated a clear association between severity of hearing loss and dementia.

Prevalence of dementia among the participants with moderate/severe hearing loss was 61% higher than prevalence among participants who had normal hearing. Hearing aid use was associated with a 32% lower prevalence of dementia in the 853 participants who had moderate/severe hearing loss.

Researchers collected data through in-home testing and interviews, and said this method allowed them to include vulnerable populations who may not have been able to visit a clinic and participate in past studies.

How hearing loss is linked to dementia isn’t yet clear, and studies point to several possible mechanisms. Huang’s research adds to a body of work by the Cochlear Center for Hearing and Public Health examining the relationship between hearing loss and dementia.

The study authors expect to have a fuller picture of the effect of hearing loss treatment on cognition and dementia from their Aging and Cognitive Health Evaluation in Elders (ACHIEVE) Study. Results from the three-year randomised trial are expected this year.

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