New JAMA study links hearing loss in older adults to dementia

A new study, led by researchers at the Johns Hopkins Bloomberg School of Public Health, found that older adults with more severe hearing loss were more likely to develop dementia, but hearing aid users were less
likely to develop dementia than those who did not use hearing aids.
The findings, from a nationally representative sample of more than 2,400 older adults, are consistent with previous findings suggesting that hearing loss may be a factor contributing to dementia risk over time, and that treating hearing loss may reduce dementia risk
.

On Jan.
10, the Journal of the American Medical Association published a study online highlighting the findings
.

"This study refines the link we observed between hearing loss and dementia and supports public health initiatives to improve access to hearing care," said lead author Dr.
Alison Huang, a senior research associate in the Department of Epidemiology and the Cochlear Hearing and Public Health Center at the Bloomberg School and a Bloomberg School Ph.
D.
in public health.

Hearing loss is a serious public health problem that affects two-thirds of Americans
over the age of 70.
The growing recognition that hearing loss can be linked to dementia risk and other adverse outcomes that affect millions of people has prompted attention to the implementation of possible strategies
to treat hearing loss.

In the new study, Huang and colleagues analyzed a nationally representative dataset
from the National Health and Aging Trends Study (NHATS).
NHATS, funded by the National Institute on Aging, has been running since 2011 and uses a national sample of Medicare beneficiaries over the age of 65, with a focus on people 90 and older, as well as blacks
.

The analysis, which included 2,413 people, about half of whom were over the age of 80, showed a clear association
between hearing loss severity and dementia.
The prevalence of dementia was 61%
higher among participants with moderate/severe hearing loss than among participants with normal hearing.
Among 853 participants with moderate/severe hearing loss, hearing aid use was associated with
a 32% reduction in dementia prevalence.

The authors note that the limitation of many past studies is that they rely on data collected in clinics and ignore vulnerable populations
who do not have the means or ability to go to clinics.
In their study, the researchers collected data from participants through home tests and interviews
.

The link between hearing loss and dementia is unclear, and studies point to several possible mechanisms
.
Huang's research complements a range of work by the Cochlear Hearing and Public Health Center to study the relationship between
hearing loss and dementia.

The study authors hope to gain a more complete understanding of the impact
of hearing loss treatment on cognition and dementia from their Aging and Cognitive Health Assessment for Older Adults (ACHIEVE) study.
Results from the three-year randomized trial are expected this year
.