Hearing loss accelerates brain function decline in older adults

January 21, 2013, Johns Hopkins University School of Medicine

Older adults with hearing loss are more likely to develop problems thinking and remembering than older adults whose hearing is normal, according to a new study by hearing experts at Johns Hopkins.

In the study, volunteers with hearing loss, undergoing repeated cognition tests over six years, had cognitive abilities that declined some 30 percent to 40 percent faster than in those whose hearing was normal. Levels of declining brain function were directly related to the amount of hearing loss, the researchers say. On average, older adults with hearing loss developed a significant impairment in their 3.2 years sooner than those with normal hearing.

The findings, to be reported in the JAMA Internal Medicine online Jan. 21, are among the first to emerge from a larger, ongoing study monitoring the health of older blacks and whites in Memphis, Tenn., and Pittsburgh, Pa. Known as the Health, Aging and , or Health ABC study, the latest report on older adults involved a subset of 1,984 men and women between the ages of 75 and 84, and is believed to be the first to gauge the impact of hearing loss on higher brain functions over the long term. According to senior study investigator and Johns Hopkins otologist and Frank Lin, M.D., Ph.D., all study participants had normal brain function when the study began in 2001, and were initially tested for hearing loss, which hearing specialists define as recognizing only those sounds louder than 25 decibels.

"Our results show that hearing loss should not be considered an inconsequential part of aging, because it may come with some serious long-term consequences to healthy brain functioning," says Lin, an assistant professor at the Johns Hopkins University School of Medicine and the university's Bloomberg School of Public Health.

"Our findings emphasize just how important it is for physicians to discuss hearing with their patients and to be proactive in addressing any hearing declines over time," says Lin. He estimates that as many as 27 million Americans over age 50, including two-thirds of men and women aged 70 years and older, suffer from some form of hearing loss. More worrisome, he says, only 15 percent of those who need a hearing aid get one, leaving much of the problem and its consequences untreated.

Possible explanations for the cognitive slide, Lin says, include the ties between hearing loss and social isolation, with loneliness being well established in previous research as a risk factor for cognitive decline. Degraded hearing may also force the brain to devote too much of its energy to processing sound, and at the expense of energy spent on memory and thinking. He adds there may also be some common, underlying damage that leads to both hearing and cognitive problems.

Lin and his team already have plans under way to launch a much larger study to determine if use of hearing aids or other devices to treat in might forestall or delay cognitive decline.

In the latest study, which began in 1997, all participants were in good general physical health at the time. Hearing tests were given to volunteers in 2001, during which they individually listened to a range of soft and loud sounds, from 0 decibels to 100 decibels, in a soundproof room.

Brain functioning was also assessed in 2001, using two well-recognized tests of memory and thinking ability, known as the Modified Mini-Mental State (3MS) and Digit Symbol Substitution (DSS), respectively. Included in the 3MS test, study participants were asked to memorize words, given commands or instructional tasks to follow, and asked basic questions as to the correct year, date and time. In the DSS test, were asked to match specific numbers to symbols and timed on how long it took them to complete the task. Both types of tests were repeated for each study participant three more times until the study ended in 2007, to gauge cognitive decline. Factors already known to contribute to loss of were accounted for in the researchers' analysis, including age, high blood pressure, diabetes and stroke.

Explore further: Hearing aid gap: Millions who could benefit remain untreated

More information: JAMA Intern Med. Published online January 21, 2013. doi:10.1001/jamainternmed.2013.1868
Related research letter: JAMA Intern Med. Published online January 21, 2013. doi:10.1001/jamainternmed.2013.1880

Related Stories

Hearing aid gap: Millions who could benefit remain untreated

February 13, 2012
Though an estimated 26.7 million Americans age 50 and older have hearing loss, only about one in seven uses a hearing aid, according to a new study led by Johns Hopkins researchers.

Hearing loss linked to 3-fold risk of falling

February 27, 2012
Hearing loss has been linked with a variety of medical, social and cognitive ills, including dementia. However, a new study led by a Johns Hopkins researcher suggests that hearing loss may also be a risk factor for another ...

One in five Americans has hearing loss: study

November 14, 2011
Nearly a fifth of all Americans 12 years or older have hearing loss so severe that it may make communication difficult, according to a new study led by Johns Hopkins researchers and published in the Nov. 14 Archives of Internal ...

Recommended for you

Sleep better, lose weight?

January 17, 2018
(HealthDay)—Sleeplessness could cost you when it's time to stand on your bathroom scale, a new British study suggests.

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

Teens likely to crave junk food after watching TV ads

January 15, 2018
Teenagers who watch more than three hours of commercial TV a day are more likely to eat hundreds of extra junk food snacks, according to a report by Cancer Research UK.

Can muesli help against arthritis?

January 15, 2018
It is well known that healthy eating increases a general sense of wellbeing. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now discovered that a fibre-rich diet can have a positive influence ...

Your dishwasher is not as sterile as you think

January 13, 2018
(HealthDay)—Your dishwasher may get those plates spotless, but it is also probably teeming with bacteria and fungus, a new study suggests.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.