Understanding the Correlation Between Hearing Loss and Dementia

In a research letter written by Alison R. Huang, PhD, and her colleagues, she discusses the correlation between hearing loss and dementia. According to the letter published in JAMA, hearing loss is related to 8% of dementia cases worldwide. Considering that, the researchers conducted a study to understand better the link and the role that hearing aids may play as a prevention tool.

The researchers gathered data from the National Health and Aging Trend Study (NHATS), focusing on Medicare beneficiaries older than 65 who were not in a nursing home or residential care setting. Of the 2,413 participants that were included in this analysis, roughly half were over the age of 80. Additionally, demographic data revealed that the majority of participants were White.

According to the study, roughly 10.27% of the patients had dementia. Approximately 36.74% of the patient population had mild hearing loss, and 29.79% had moderate to severe hearing loss.

Furthermore, hearing loss correlated with a higher incidence of dementia. Patients with normal hearing had a dementia incidence as low as 6.19%. Conversely, patients with moderate or severe hearing loss had a 16.52% chance of dementia. Meanwhile, mild hearing loss fell somewhere in between at an 8.93% risk of dementia.

Additional data was collected on how the use of hearing aids impacted dementia risk. According to the analysis, those with moderate-to-severe hearing loss who used hearing aids were 32% less likely to develop dementia than those who did not use hearing aids.

Currently, the WHO estimates that 55 million people worldwide have dementia. Many sources, including Alzheimer's Disease International, expect that number to grow to 139 million by 2050 and double every 20 years. The increasing prevalence of dementia, partially linked to population aging, represents a significant burden on healthcare systems.

However, studies such as this one, which identifies factors that may contribute to the onset of dementia, may help providers diagnose it sooner, implement treatment earlier, and delay advanced disease progression. Additionally, data on hearing aid use may help providers prevent dementia in some patients experiencing or at risk for hearing loss. Newly available over-the-counter hearing aids, which have improved patient access to hearing aids, may also help combat the rising rates of dementia.

Despite the critical information this study provided, it had some limitations, requiring further research to understand the association between dementia and hearing loss. “Mediation analyses to characterize mechanisms underlying the association and randomized trials to determine the effects of hearing interventions on reducing dementia risk are needed,” noted Huang and her colleagues in the article.