Study links untreated hearing loss to cognitive decline in older adults

While age-related hearing loss has long been linked to cognitive decline, a UK study suggests hearing aids may help minimize the risk of problems like impaired memory or executive function.

Researchers examined data on 7,385 adults 50 and older without a diagnosis of dementia or other conditions tied to cognitive problems and without hearing implants or ear infections. Overall, about 41 percent had mild hearing loss, 10 percent had severe hearing loss, and 11 percent used a hearing aid.

People with mild to moderate hearing loss did score lower on memory assessments than individuals with perfect hearing, the study found. But this was only true for people who didn’t use hearing aids.

“Not correcting for hearing loss results in social isolation which in turn results in us not utilizing many of our neural networks in the brain on a regular basis,” said study co-author Gurleen Popli of the University of Sheffield, in an email. “This could possibly explain the cognitive decline.”

People in the study who used hearing aids, however, were very different from individuals who didn’t use these devices, the researchers report in JAMA Otolaryngology Head and Neck Surgery.

Hearing aid users tended to have moderate to severe hearing loss rather than just mild hearing loss. They also tended to be older, to live alone, and to have high blood pressure - all independent risk factors for cognitive decline.

About one in three adults ages 65 to 74 have hearing loss, and almost half of people older than 75 have trouble hearing, according to the U.S. National Institutes of Health.

Age-related hearing loss can lead to a wide variety of health problems, as it touches on many aspects of daily life, making it harder for people to keep up with conversations, maintain a normal social life and follow a doctor’s advice about medical problems.

Previous studies have indicated that age-related hearing loss may be a risk factor for dementia. However, results from individual studies have been inconsistent, possibly due to differences in methods such as the type of hearing assessment used.

It’s also not clear how age-related hearing loss and cognitive decline are related, and the study wasn’t a controlled experiment designed to answer this question.

Results from the study in the UK, where hearing aids may be covered by the National Health Service, may differ from what would happen in the U.S. and other countries where many people may need to pay out-of-pocket for hearing aids.

Still, the results suggest it would make sense to screen people 50 and older for hearing loss and treat it as early as possible to potentially delay or prevent the onset of dementia or cognitive impairment, said Dr. Francesco Panza of the University of Bari Aldo Moro in Italy.

“Age-related hearing loss may represent a modifiable condition and a possible target for secondary prevention of cognitive impairment in older age, social isolation, late-life depression, and frailty,” Panza, who wasn’t involved in the study, said by email.