|
 When researchers used a stricter threshold to include mild hearing
loss, they found evidence that the well-established link between
age-related hearing loss and cognitive decline might begin sooner
than is recognized, according to the report in JAMA
Otolaryngology-Head & Neck Surgery.
The seniors who had hearing problems at the more sensitive threshold
would have been considered to have normal hearing by the current
standard for diagnosing hearing loss: 25 decibels, the researchers
note. But when the threshold was set at a hearing decline of just 15
decibels, which is comparable to the volume of a whisper or rustling
leaves, some of the seniors had trouble hearing.
These people also had "clinically meaningful" cognitive decline, the
study team found.
Some scientists suspect that hearing issues might lead to thinking
problems because the brain has to redirect so much attention to
hearing that it doesn't get to exercise other mental functions as
much.
"People with worse hearing use so much more brainpower to decode the
words that are said, they don't get to process the meaning of what
was said, which is the intellectually stimulating part," said the
study's lead author, Dr. Justin Golub, an assistant professor in the
department of otolaryngology-head and neck surgery at NewYork-Presbyterian/Columbia
University Irving Medical Center in New York City.
Golub compares brain fitness to physical fitness. If runners had to
think about how to take each step, they wouldn't get very fast, he
explained. Similarly, parts of the brain involved in complex
thinking don't get as much "exercise" when more resources are
directed to decoding the words in a conversation.
Beyond that, it's been shown that "people with worse hearing
socialize less - because it's hard - and thus have fewer
intellectually stimulating conversations," Golub said. "The brain is
like a tool that has to be maintained."
For the new study, Golub and his colleagues analyzed information
from the Hispanic Community Health Study (HCHS) and the National
Health and Nutrition Study (NHANES), both of which contained data on
participants who were given both hearing and cognitive testing.
The researchers focused on participants in the HCHS who were aged 50
or older and who had not developed early-onset hearing loss and
those in the NHANES who were aged 60 to 69. That gave them a total
of 6,451 people in the analysis, with an average age of just over 59
years.
[to top of second column] |
After accounting for demographic and cardiovascular risk factors -
both of which might impact the likelihood of developing cognitive
problems - the researchers determined that decreased hearing ability
was associated with worse performance on the cognitive tests.
"People who had difficultly hearing a whisper (but technically still
had normal hearing), scored 6 points worse on a test of speed and
attention than people who had absolutely perfect hearing," Golub
said in an email. "This took into account other factors, such as
age. Scientists say that the 6-point change could make a meaningful
difference in day to day function."
The study wasn't designed to examine how hearing loss might directly
influence cognitive decline, the researchers acknowledge.
Still, Golub suspects that people might be able to remain more
mentally sharp if they started wearing hearing aids as soon as they
started to have even mild issues with hearing.
In fact, he said, "we're running a randomized controlled trial right
now treating one group of people with hearing loss and comparing
them to a group with no treatment. We'll see if in a couple of years
the people with hearing aids are cognitively sharper."
Golub and his colleagues looked at something other researchers
haven't considered: the possible impact of mild hearing loss on
cognition, said Dr. Maura Cosetti, an associate professor at the
Icahn School of Medicine and director of the Cochlear Implant Center
at New York Eye and Ear Infirmary of Mount Sinai in New York City.
Lately, Cosetti said, researchers increasingly have been wondering
"if we treat hearing loss can we improve cognition or at least
stabilize the rate of decline. It seems like the answer is yes, but
it's too early to tell."
Unfortunately, many people who have developed hearing problems are
unwilling to use a hearing aid, Cosetti said. "It's something
ingrained in our culture," she added.
SOURCE: https://bit.ly/33ZACA4 and https://bit.ly/2OpIy7x JAMA
Otolaryngology-Head & Neck Surgery, online November 14, 2019.
[© 2019 Thomson Reuters. All rights
reserved.] Copyright 2019 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
Thompson Reuters is solely responsible for this content. |
