Hearing Loss Further Linked to Risk of Dementia

People with severe hearing loss have up to a 20% increased risk of dementia compared to those with no hearing loss.

Hearing loss is associated with the risk of dementia and the risk is notably higher for those who do not use hearing aids, according to findings of the largest study of its kind, which was published this month in JAMA Otolaryngology-Head & Neck Surgery.

However, the 7% higher risk for dementia among those with hearing loss in this study of 573,088 people in southern Denmark is considerably lower than in previous studies, “highlighting the need for more high-quality longitudinal studies,” wrote Manuella Lech Cantuaria, PhD, with the University of Southern Denmark in Odense, and colleagues.

Dr. Cantuaria said her team speculated that because the proportion of hearing aid users in Denmark is generally higher than in many other countries, that may have affected findings. “If it is true that hearing aid treatment can reduce the risk for dementia, this could potentially explain the lower risk rates observed in our study,” she told MedCentral.

She added that differences can also be partly explained by the methodological approaches utilized. Her team wrote that previous studies also included smaller cohorts with limitations such as males-only, volunteers, or people within a specific age group.

Hearing Loss and Dementia Study Spanned 14 Years

The study was conducted in southern Denmark between January 2003 and December 2017 and included all residents at least 50 years old. Researchers excluded all people with dementia at baseline.

Key findings include that people with severe hearing loss have up to a 20% increased risk of dementia compared to those with no hearing loss.

Dementia risk was also 20% higher for people with hearing loss who do not wear hearing aids compared to those with normal hearing. Using hearing aids was linked with a 6% higher risk of developing dementia.

“Our study suggests that treating hearing loss seems to be an important step in preventing dementia or postponing dementia symptoms,” Dr. Cantuaria said.

Jan Blustein, MD, PhD, research professor of population health at New York University Grossman School of Medicine in New York City, who was not part of the study, pointed to ongoing confusion in understanding the link between dementia and hearing loss.

“Many have understood the statement that hearing loss increases risk for dementia as saying that hearing loss somehow ‘plants a seed’ of dementia, or that hearing loss is a prodrome for dementia. That almost certainly is not the correct interpretation.”

She explained that this confusion was further confounded by the UK Biobank data in the retracted Jiang et al study published last year in Lancet Public Health. While Jiang et al concluded that hearing aid use mitigates dementia risk, their study was retracted because the findings “were reversed in a coding error,” noted Dr. Blustein.

Better Hearing Is Always Valuable

What is clear, Dr. Blustein said, is that better hearing is valuable at any age and enriches both social connection and wellbeing.

Primary care providers can encourage patients to take any hearing loss seriously regardless of the link to dementia, she suggested.

Over-the-counter hearing aids, she noted, may be better for tech-savvy patients, although they are a more affordable option for all. The nonprofit group Hearing Loss Association of America also offers a patient guide to buying OTC hearing aids.

Disclosures: Dr. Cantuaria and several coauthors reported grants from the William Demant Foundation during the conduct of the study. Coauthor Dr. Schmidt also reports grants from Innovation Foundation Denmark, Interfond, Oticon, GN Hearing and Widex-Sivantos. Dr. Blustein reported no relevant financial relationships.