New research reveals a surprising link between hearing loss and dementia in the elderly
The findings highlight the potential benefit of hearing aids.
A new study found that older adults with severe hearing loss were more likely to develop dementia, but the likelihood of developing dementia was lower among hearing aid users compared to non-users. The research was led by scientists at the Johns Hopkins Bloomberg School of Public Health.
The findings, from a nationally representative sample of more than 2,400 older adults, are consistent with previous studies showing that hearing loss may be a contributing factor to dementia risk over time, and that treatment of hearing loss may reduce the risk of dementia.
The findings are highlighted in a research letter published online on January 10, 2023, in Journal of the American Medical Association.
says lead author Allison Huang, PhD, MPH, research associate in the Bloomberg School Department of Epidemiology and in the Cochlear Center for Hearing and Public Health at the Bloomberg School.
Hearing loss is a serious public health problem affecting two-thirds of Americans over the age of 70. The growing understanding that hearing loss may be associated with risk of dementia, which affects millions, and other negative outcomes, has called attention to implementing possible strategies for treating hearing loss.
For the new study, Huang and colleagues analyzed a nationally representative data set from the National Health and Aging Trends Study (NHATS). Funded by the National Institute on Aging, NHATS has been ongoing since 2011, and uses a national sample of Medicare beneficiaries over the age of 65, focusing on the 90-and-over group as well as black individuals.
The analysis included 2413 people, almost half of whom were over 80 years of age and showed a clear association between the severity of hearing loss and dementia. The prevalence of dementia among participants with moderate/severe hearing loss was 61 percent higher than the prevalence of dementia among participants with normal hearing. Hearing aid use was associated with a 32 percent lower prevalence of dementia in 853 participants with moderate/severe hearing loss.
The authors note that many of the previous studies were limited in that they relied on clinic data collection, which excluded vulnerable populations who did not have the means or ability to access a clinic. For their study, the researchers collected data from participants through at-home tests and interviews.
It is not yet clear how hearing loss is linked to dementia, and studies point to several possible mechanisms. Huang’s research adds to the body of work of the Cochlear Center for Hearing and Public Health examining the relationship between hearing loss and dementia.
The study authors expect to get a fuller picture of the impact of hearing loss treatment on cognition and dementia from the Aging and Cognitive Health Evaluation in Older Adults (ACHIEVE) study. Results of the three-year randomized trial are expected this year.
Hearing impairment and prevalence of dementia in older adults in the United States was co-authored by Allison Huang, Kening Jiang, Frank Lin, Jennifer Dale, and Nicholas Reed.
Reference: “Hearing Loss and Prevalence of Dementia in Older Adults in the United States,” by Alison R. Huang, Ph.D.; Kening Jiang, MHS; Frank R. Lynn, MD, PhD; Jennifer A. Dell, Ph.D. and Nicholas S. Reid, Australia, Jan. 10, 2023, Available Here. gamma.
Support for the research was provided by the National Institute on Aging (K23AG065443, K01AG054693).
Reported Co-Author Disclosures: Nicholas Reed, American University in Dubai, serves on the Scientific Advisory Board for Neosensory. Frank Lane, MD, PhD, is a consultant to Frequency Therapeutics and Apple and director of a research center funded in part by a charitable gift from Cochlear Ltd to the Johns Hopkins Bloomberg School of Public Health. Lynn is also a board member of the nonprofit Access Hears.