Long suspected by medical professionals, dementia, the age-related cognitive decline, is accelerated in older persons with hearing loss.
In what may be the first randomized controlled trial of its kind, a new study that was just published in The Lancet on Tuesday explores the relationship between the two disorders in more detail.
Worldwide, dementia affects more than 55 million people, a number that is rising as more people live longer. For a number of reasons, hearing loss has become one of the likely risk factors for dementia.
Scientists speculate that as the brain struggles to hear, it may be less capable of thinking or remembering. Less sound absorption causes the brain to shrink more quickly.
Additionally, hearing loss might result in social isolation, which can reduce cognitive engagement in older people.
There hasn’t been a randomized, controlled experiment to determine the effect of hearing loss on cognitive decline or whether wearing hearing aids actually lowers any potential risk, despite numerous studies exploring and hypothesizing this association.
It was only lip service, according to Frank Lin, a professor at the Johns Hopkins Bloomberg School of Public Health and the study’s primary investigator.
“I’d hear, ‘oh, someone’s getting older, they should get their hearing treated,’ but it was just lip service,” Lin said. Because some of those fundamental questions weren’t addressed, I came to the realization that little progress was being made.
These topics were the focus of the ACHIEVE project, which the National Institutes of Health funded and began in November 2017. Nearly 1,000 adults between the ages of 70 and 84 were monitored during the research.
One-fourth came from an observational heart health research, and on average, they had greater dementia risk factors. They were more likely to be single, older, have lower incomes, and have higher blood pressure.
Volunteers who did not participate in the heart health study made up the remaining three quarters. In comparison to the control group’s heart study participants, those participants were thought to be generally healthier.
Half of the participants in each group were given hearing aids and routine hearing care at random, while the other half got fundamental health education every six months. After three years, the researchers assessed how each participant’s cognition had changed.
After three years, according to a number of cognitive tests, the study found no discernible difference between individuals who used hearing aids and those who didn’t in the pace or prevalence of cognitive deterioration.
These assessments, which included logical memory and delayed word recall, were carried out yearly. Additionally, in the healthier control sample, hearing aids were not associated with a reduced risk of cognitive change.
However, after three years, people who wore hearing aids had 48% less cognitive change than those who didn’t in the group thought to be at higher risk of dementia.
The results, according to Rebecca Lewis, head of audiology at University of California, San Francisco, will assist highlight the value of hearing aids for patients who are at risk of or are currently experiencing dementia.
On the other hand, if they have not yet sought treatment for their hearing loss, it will assist individuals at lesser risk breathe more easily.
“People who don’t necessarily have cognitive decline or those risk factors can say, ‘Oh, OK, if I waited two more years, this isn’t going to do me a disservice,” said Lewis, who was not involved in the study.
But individuals who actually do struggle with cognitive functioning need to keep this in the forefront of their minds.
Lin believed that the healthy control cohort’s lack of change made sense since “they didn’t have much cognitive change to begin with” that would have allowed for the observation of a large shift over three years.
Lewis agreed with Lin that one of the study’s weaknesses is its duration; it’s feasible that hearing aids will assist populations that are healthier over a longer period of time.
She also mentioned that not just hearing aids were given to the group receiving treatment for hearing loss.
They had access to high-quality audiology care, which included routine visits and maintenance on their equipment.
“This is really top-level audiology that they’ve provided, it’s not just a ‘let’s plug in some hearing aids and send you on your way,'” Lewis, who most recently worked at hearing aid start-up Whisper, said.
Would the same strategy work if those individuals had hearing aids purchased without consulting an audiologist? That isn’t why I think it would be the case.
The study’s failure to blind the groups to the type of treatment they received means that the placebo effect was not taken into account.
According to Lin, they discussed the potential of using fake hearing aids, but we felt that would have deterred participants from participating in the study.
This past fall, the Food and Drug Administration began to permit over-the-counter hearing aids, opening the door for device manufacturers and tech companies to market sleeker, more compact solutions.
However, the majority of insurers do not pay for the devices, therefore many patients cannot obtain them.
Lin hopes that the study’s findings would rekindle interest in the Centers for Medicare and Medicaid Services’ (CMS) recent discussion of paying for prescription hearing aids.
Getting together with our congressional policymakers, who were really supportive of the Medicare benefit a few years ago, and seeing if we can revive that, Lin said, is “a big push for us in the next several months.”
