Hearing aids may protect against increased dementia risk associated with hearing loss, study suggests
A study of 437,704 people suggests that those who experience hearing loss and do not use hearing aids may have a higher risk of dementia than people without hearing loss. Those who used hearing aids did not appear to have an increased risk of dementia.
After adjusting for other factors, the study analysis suggests a 1.7% risk of dementia in people with hearing loss who do not use hearing aids, compared to 1.2% among people without hearing loss or who experience hearing loss. but they use headphones.
The authors call for greater public awareness of the potential protective effects of hearing aids against dementia, greater accessibility to hearing aids by reducing costs, and more support for primary care workers to detect hearing impairments, raise awareness, and provide treatment, such as fitting hearing aids.
People with hearing loss who do not use hearing aids may have a higher risk of dementia than people without hearing loss, suggests a new study published in the journal The Lancet Public Health . However, using a hearing aid can reduce this risk to the same level as people without hearing loss.
Dementia and hearing loss are common conditions among older adults. The Lancet Commission on Dementia Prevention, Intervention and Care, published in 2020, suggested that hearing loss may be linked to around 8% of dementia cases worldwide, therefore addressing hearing impairment could be a crucial way to reduce the global burden of dementia.
“Evidence is accumulating that hearing loss may be the most impactful modifiable risk factor for dementia in midlife, but the effectiveness of hearing aid use in reducing real-world dementia risk remains unclear.” . “Our study provides the best evidence to date to suggest that hearing aids could be a cost-effective and minimally invasive treatment to mitigate the potential impact of hearing loss on dementia,” says corresponding author Prof. Dongshan Zhu of the University from Shandong (China).
The researchers analyzed data from 437,704 people who were part of the UK Biobank database. Information on the presence of hearing loss and hearing aid use was collected through self-administered questionnaires, and dementia diagnoses were determined using hospital records and death registry data. The average age of study participants at recruitment was 56 years and the average follow-up time was 12 years .
About three-quarters of participants (325,882/437,704) had no hearing loss, and the remaining quarter (111,822) had some level of hearing loss. Among people with hearing loss, 11.7% (13,092 / 111,822) used hearing aids.
After controlling for other factors, the study suggests that compared with participants with normal hearing, people with hearing loss who did not use hearing aids had a 42% increased risk of all-cause dementia, while no increased risk was found. risk in people with hearing loss who use hearing aids.
This equates to approximately a 1.7% risk of dementia in people with hearing loss who do not use hearing aids, compared to 1.2% among people without hearing loss or who experience hearing loss but use hearing aids.
“About four-fifths of people experiencing hearing loss do not use hearing aids in the UK. Hearing loss can begin as early as age 40, and there is evidence that gradual cognitive decline before a dementia diagnosis can last 20 to 25 years. Our findings highlight the urgent need for the early introduction of hearing aids when someone begins to experience a hearing impairment . A society-wide group effort is needed, including raising awareness of hearing loss and possible links to dementia, increasing accessibility to hearing aids by reducing cost, and more support for primary care workers to screen for hearing impairment. , raise awareness and provide treatment. such as fitting hearing aids,” says Dongshan Zhu.
The researchers also looked at how other factors, such as loneliness, social isolation, and depressive symptoms , could affect the association between hearing loss and dementia. The study analysis suggests that less than 8% of the association between hearing aid use and decreased dementia risk could be eliminated by improving psychosocial problems. The authors say this indicates that the association between hearing aid use and protection against increased dementia is likely due primarily to the direct effects of hearing aids rather than the indirect causes investigated.
“The underlying pathways that may link hearing aid use and dementia risk reduction are unclear. “More research is needed to establish a causal relationship and the presence of underlying pathways,” says study author Dr. Fan Jiang of Shandong University, China.
The authors acknowledge some limitations of the study, including that self-report is at risk of bias and that, since this study is observational, the association between hearing loss and dementia could be due to reverse causality through neurodegeneration or other shared mechanisms. . Additionally, although many cofactors were taken into account, there may be unmeasured factors, such as those who used hearing aids possibly also took better care of their health than those who did not use them. Finally, the majority of UK Biobank participants are white, and very few participants were born deaf or experienced hearing loss before acquiring spoken language, which may limit the generalizability of the findings to other ethnicities and people with limited hearing. who use sign language.
Writing in a linked comment, Professor Gill Livingston and Dr Sergi Costafreda, University College London , who were not involved in this research, said: "With the addition of the work of Jiang and colleagues, the evidence that hearing aids are an powerful tool to reduce the risk of dementia in people with hearing loss is best possible without randomized controlled trials, which may not be practically possible or ethical because people with hearing loss should not be prevented from using effective treatments. is not only a disease that affects the individual and their family, but it can also be expensive. However, the use of hearing aids to prevent dementia has been found to be cost-effective and economical. In the US, hearing aids are available to purchase without a prescription, making them more accessible. The evidence is compelling that treating hearing loss is a promising way to reduce the risk of dementia. “Now is the time to increase awareness and detection of hearing loss, as well as the acceptability and usability of hearing aids.”
In conclusion , compared to people with normal hearing, people with hearing loss had a 42% increased risk of dementia, and hearing aid use was associated with a similar risk of dementia as people without hearing loss. Associations were seen in both all-cause dementia and cause-specific dementia subtypes (Alzheimer’s disease, vascular dementia, and non-Alzheimer’s disease-related non-vascular dementia).
Well-designed clinical trials are needed to evaluate the effect of hearing aid use on dementia risk and to qualify the role of hearing aid types and duration of hearing aid use for dementia prevention in different types of hearing impairment.
Despite the beneficial effects, most people with hearing loss do not use hearing aids.35 Hearing loss can begin as early as age 40, and the prodromal phase of dementia also lasts 20 to 25 years. Our findings highlight the urgent need to take action to address hearing loss across the life course to improve cognitive decline. Public health strategies are necessary to raise awareness of hearing loss and the potential harm of untreated hearing impairment, increase accessibility to hearing aids by reducing cost, encourage screening, and provide potential interventions such as hearing aid fitting.
Added value of this study We examined the association between hearing aid use and incident dementia (all-cause and cause-specific dementia of Alzheimer’s disease, vascular dementia, and non-vascular dementia unrelated to Alzheimer’s disease) and the mechanisms underlying these associations. Hearing loss was associated with an increased risk of dementia, and hearing aid use was associated with a risk of dementia at a similar level to people without hearing loss. Associations with hearing aid use were seen in all-cause dementia and cause-specific dementia. Analyzes suggested that the observed association between hearing aid use and dementia risk reduction was primarily related to so-called direct effects of hearing aid use, with measured indirect effects representing less than 8% for each potential mediator. Implications of all available evidence In people with hearing loss, the use of hearing aids could reduce the risk of dementia. With the suggestion that up to 8.2% of dementia cases could be prevented by preventing hearing loss, our findings could have important clinical and public health implications. If causality is established, hearing aids could present a cost-effective, minimally invasive intervention to mitigate all or at least some of the effects of hearing loss in dementia. |
This study was funded by the National Natural Science Foundation of China and Shandong Province, the Taishan Scholars Project, the China Medical Board, and the China Postdoctoral Science Foundation.
