Study links hearing loss to increased risk of developing dementia in older adults

An American survey found a link between hearing loss and a higher prevalence of dementia in the elderly over 70 years old.

According to the study, the prevalence of dementia is greater the greater the degree of hearing loss, reaching 16.52% with severe hearing loss. The same rate was 6.19% in patients with normal hearing and 8.93% for those with mild hearing loss.

Comparing patients with some type of hearing impairment with those without symptoms, the prevalence is 61% higher.

On the other hand, the use of hearing aids in those who already had signs of hearing impairment reduced the risk of dementia by 32% compared to those who did not use the device.

The research findings were published last Tuesday (10) in the specialized journal Jama (Journal of the American Medical Association) by researchers from the Cochlear Center for Hearing and Public Health at the Bloomberg School of Public Health, Johns Hopkins University, in the United States.

To assess the role of hearing loss in the prevalence of dementia, the scientists analyzed data obtained through surveys and community surveys —excluding patients in long-term care facilities for the elderly— of 2,413 patients aged 65 years or older enrolled in the health insurance program. of Medicare health, linked to the government.

Of the total participants, 1,347 (55.8%) were women and 1,285 (53.3%) were 80 years old or older. Among ethnicities and skin color, 453 (18.8%) were non-Latin black, 110 (4.6%) were Latino, and 1,790 (74.2%) were non-Latin white.

Considering the variables of gender, age, education, race and ethnicity, smoking history and preexisting health conditions (such as having had a stroke, heart disease or hypertension, among others), the total prevalence of dementia in the population was 10.27% . The higher incidence of dementia was associated with males, older people and people with less education, as already indicated in other studies.

The estimated rate of hearing loss was 36.74% in the study participants.

According to the authors, the risk of dementia increased by about 16% for every ten decibels lost in the auditory analysis, which indicates that the greater the hearing loss, the greater the prevalence of cognitive damage as well.

For Alison Huang, first author of the study and an associate researcher at the medical center, the research provides more accurate data on what was already observed in the medical literature. “The study refines this observed link between hearing loss and dementia and supports public health action to improve access to hearing aids, especially for the elderly,” she said.

Still according to the study, the prevalence of global hearing loss in patients with dementia is around 8%.

In Brazil, the latest available data on hearing loss in the elderly are from the 2019 National Health Survey (PNS), which identified 1.5 million elderly people with hearing impairment. The numbers are a little below the prevalence indicated by the WHO, of 1.5% of people with hearing loss in the country – which would give about 3 million people.