(Reuters Health) – Small declines in hearing, smaller than the usual cutoff for diagnosing hearing loss, are associated with measurable mental decline in the elderly, a new study suggests.
When the 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 may begin earlier than recognized, according to the JAMA report. Head and neck surgery.
Elderly people who had hearing problems at the most sensitive threshold would be considered to have normal hearing by the current standard for the diagnosis of 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 rustle of leaves, some of the elderly had trouble hearing.
These people also had "clinically significant" cognitive decline, according to the study team.
Some scientists suspect that hearing problems can lead to thinking problems because the brain needs to redirect so much attention to hearing that it cannot perform other mental functions.
"People with poorer hearing use much more intelligence to decode the words spoken, they cannot process the meaning of what has been said, which is the intellectually stimulating part," said lead author Dr. Justin Golub. , assistant professor in the department of head and neck otolaryngology at NewYork-Presbyterian / Columbia University Irving Medical Center in New York.
Golub compares brain fitness to physical fitness. If runners needed to think about how to take each step, they wouldn't be too fast, he explained. Similarly, parts of the brain involved in complex thoughts do not receive as much "exercise" as more resources are directed to decoding words in a conversation.
In addition, it has been shown that "people with poorer hearing socialize less – because it's difficult – and therefore have fewer intellectually stimulating conversations," Golub said. "The brain is like a tool that needs 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), which contained data from participants who received hearing and cognitive tests.
The researchers focused on HCHS participants 50 years of age and older who did not develop early-onset hearing loss and those in NHANES aged 60 to 69 years. This gave them a total of 6,451 people in the analysis, with an average age of just over 59 years.
After considering demographic and cardiovascular risk factors – which may affect the likelihood of developing cognitive problems – the researchers determined that decreased hearing ability was associated with poorer performance on cognitive tests.
"People who heard a hard whisper (but technically still had normal hearing) scored 6 points worse on a speed and attention test than people who had absolutely perfect hearing," Golub said in an email. “This took into account other factors, such as age. Scientists say the 6-point shift can make a significant difference in everyday functions. "
The study was not designed to examine how hearing loss can directly influence cognitive decline, the researchers acknowledge.
Still, Golub suspects that people can stay mentally sharper if they start wearing hearing aids as soon as they start having mild hearing problems.
In fact, he said, "We're currently conducting a randomized controlled trial, treating a group of people with hearing loss and comparing them to an untreated group. We'll see if, in a few years, people with hearing aids will be cognitively sharper . "
Golub and his colleagues looked at something other researchers did not consider: the possible impact of mild hearing loss on cognition, said Dr. Maura Cosetti, associate professor at Icahn School of Medicine and director of the New York Eye Cochlear Implant Center and heard from Mount Sinai in New York.
Lately, Cosetti said, researchers have increasingly wondered, “If we treat hearing loss, can we improve cognition or at least stabilize the rate of decline. It seems the answer is yes, but it is too early to know. "
Unfortunately, many people who have developed hearing problems are unwilling to wear a hearing aid, Cosetti said. "It is ingrained in our culture," he added.
SOURCE: bit.ly/33ZACA4 and bit.ly/2OpIy7x JAMA Otorhinolaryngology-Head and Neck Surgery, online November 14, 2019.