BALTIMORE — Older adults with more severe hearing loss were found more likely to develop dementia in comparison to others, according to researchers from Johns Hopkins Bloomberg School of Public Health. While these findings are no doubt worrying for the millions of older individuals who deal with varying levels of hearing loss, there is a silver lining — dementia risk was lower among people using hearing aids.
These findings come from a review of a nationally representative sample of over 2,400 older individuals. The results are largely consistent with earlier studies that concluded hearing loss may contribute to dementia risk over time. Consequently, scientists have theorized in recent years that treating hearing loss may help lower dementia risk.
“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,” says 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 a university release.
Hearing loss is incredibly common among older Americans
The issue affects roughly two-thirds of all Americans over the age of 70. The growing scientific consensus that hearing loss appears to have a connection to dementia highlights the importance of implementing possible strategies which alleviate hearing loss.
For this latest project, Dr. Huang and her colleagues analyzed a nationally representative dataset provided by the National Health and Aging Trends Study (NHATS). That project has been ongoing since 2011, uses a nationwide sample of Medicare beneficiaries over age 65, and has placed a particular focus on the 90-and-over group as well as African Americans.
In all, the analysis encompassed 2,413 people, with about half being over 80 and displaying a clear association between severity of hearing loss and dementia. Dementia prevalence among patients with moderate-to-severe hearing loss was 61 percent higher compared to participants with normal hearing. Meanwhile, the use of a hearing aid was associated with a 32-percent lower prevalence of dementia among the 853 participants dealing with moderate-to-severe hearing loss.
The new study examines hearing loss among vulnerable populations
Study authors note that numerous studies focusing on this topic were limited by the fact that they relied on in-clinic data collection. This approach left out vulnerable populations that had neither the means nor the capacity to get themselves to a clinic. For this new study, researchers collected data through in-home testing and interviews.
Precisely how hearing loss is connected with dementia is still unclear, but prior work points to a few possible explanations. Dr. Huang’s research in particular adds to a body of work started by the Cochlear Center for Hearing and Public Health examining the relationship between hearing loss and dementia.
Moving forward, the research team expects to form a much more comprehensive understanding of the effect of hearing loss treatment on cognition and dementia from their Aging and Cognitive Health Evaluation in Elders (ACHIEVE) Study. The results from that three-year randomized trial are expected sometime in 2023.
The study is published in JAMA.
