In Brief | Gerontology | Neurology
The Hidden Risk: New Study Investigates How Hearing Loss May Speed Up Dementia
Time to read: 03:06
Time to listen: 04:59
Originally Published: 4 January 2024
Source: JAMA Otolaryngol Head Neck Surg
Type of article: In Brief
MedED Catalogue Reference: MNGIB010
Category:Gerontology
Cross Reference: Neurology
Keywords: dementia, hearing loss, cognitive decline
The study found that hearing loss was associated with a significantly increased risk of dementia, particularly in individuals not using hearing aids, suggesting that hearing aids may help prevent or delay the onset and progression of dementia.
This article is a review of recent studies originally published in the JAMA Otolaryngol Head Neck Surg,4 January 2024 This article does not represent the original research, nor is it intended to replace the original research. Access the full Disclaimer Information.
NEW: Watch the 60 Second Summary
(Please let us know if you like this format by clicking here)
Listen to Full Article
Study Context
The relationship between hearing loss and dementia has been a subject of debate in the literature, with some studies linking impaired hearing to cognitive decline.
The proposed mechanisms for this association include cognitive load and the reallocation of cortical resources, reduced social interaction, and shared underlying pathology between hearing loss and dementia.
The Lancet Commission on Dementia Prevention highlighted hearing loss as a significant modifiable risk factor, but the evidence remained inconclusive, primarily due to the limited scope and sample size of existing longitudinal studies.
Study Purpose
The objective of this study was to assess the association between hearing loss and the incidence of dementia, and to examine how the use of hearing aids impacts this relationship.
Study Methodology
Residents older than 50 years were included in the original sample.
Both hearing status and the incidence of dementia were identified from national registries.
Persons with dementia before baseline were excluded.
Findings
Of the 573,088 participants included in the original cohort, 23,023 developed dementia over a mean follow-up period of 8.6 years.
Hearing loss was associated with a 7% increased risk of dementia (HR 1.07), compared to individuals without hearing loss.
Severe hearing loss in the better ear increased dementia risk by 20% (HR: 1.20, 95% CI: 1.09-1.32).
Severe hearing loss in the worse ear increased dementia risk by 13% (HR: 1.13, 95% CI: 1.06-1.20).
Notably, individuals with hearing loss who did not use hearing aids had a 20% higher risk of developing dementia (HR 1.20) compared to those with hearing loss who used hearing aids, whose risk was comparatively lower (6%).
Study Discussion
The findings that severe HL appeared to be associated with a higher dementia risk, and that the risk was notably greater among individuals who did not use hearing aids aligned with several other studies.
Furthermore, the study found stronger associations with HL in the better ear, supporting the hypothesis that hearing ability in the better ear is a more accurate predictor of how HL affects patients in social and cognitively demanding situations.
The researchers note that their findings suggest that hearing aid use could reduce dementia risk, which may explain the lower risk estimates in Denmark, where hearing aid use is higher compared to other countries like the US.
However, studies on the cognitive benefits of hearing aids are still inconclusive, likely due to methodological limitations such as small sample sizes and short follow-up periods. Nonetheless, the researchers hypothesised that the association of stronger dementia in those diagnosed with HL earlier in life, is possibly due to prolonged cognitive impact.
A subanalysis revealed higher risk estimates for individuals with suspected HL compared to confirmed HL, pointing to potential misclassification in the diagnosis of Alzheimer’s disease.
Conclusion
This large cohort study suggests that hearing loss is associated with an increased risk of dementia, especially in individuals who do not use hearing aids. The findings indicate that hearing aids could potentially help delay or prevent dementia, though further studies are required to establish a definitive causal relationship.
Importance of this study for South Africa
The Hearing Loss in South Africa report, released in 2021, revealed that approximately 12 million people in the country experience some form of hearing loss. Alarmingly, less than 5% of those affected receive treatment.1
Cognitive decline—including dementia and Alzheimer’s disease—represents a significant public health challenge, with international data ranking dementia as the third most expensive disease to treat. Even more concerning, dementia affects one in three people living with HIV/AIDS.2
When considering the combined impact of hearing loss, dementia, and HIV/AIDS, the overall disease burden becomes evident. However, hearing testing—a relatively simple and accessible intervention—could support earlier detection of hearing loss and potentially help reduce the dementia-related health burden in South Africa.
Additional References
1. University of Pretoria. (n.d.). Launch of the World Report on Hearing in South Africa. University of Pretoria. Retrieved 11 March 2025 from https://www.up.ac.za/speech-language-pathology-and-audiology/news/post_2974748-launch-of-the-world-report-on-hearing-in-south-africa-
2. Dementia South Africa. (n.d.). About. Dementia South Africa. Retrieved 11 March 2025. https://www.dementiasa.org/about/
Disclaimer
This article is compiled from several resources researched and compiled by the contributor. It is in no way presented as an original work. Every effort has been made to attribute quotes and content correctly. Where possible all information has been independently verified. The Medical Education Network bears no responsibility for any inaccuracies which may occur from the use of third-party sources. If you have any queries regarding this article contact us
Fact-checking Policy
The Medical Education Network makes every effort to review and fact-check the articles used as source material in our summaries and original material. We have strict guidelines in relation to the publications we use as our source data, favouring peer-reviewed research wherever possible. Every effort is made to ensure that the information contained here is an accurate reflection of the original material. Should you find inaccuracies, out of date content or have any additional issues with our articles, please make use of the contact us form to notify us.
