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The Link Between Hearing Loss and Dementia

A new discovery gives you a new reason to check your hearing now

By Linda Childers | June 25, 2012

Need a reason to finally get your hearing checked? Try this: A new study has found that people who experience significant hearing loss as they age may also be at higher risk of developing dementia.
 
The study, conducted by researchers at Johns Hopkins University School of Medicine in Baltimore in conjunction with the National Institute on Aging, found that older adults with hearing loss were more likely to develop cognitive decline over time than those who retain their hearing. While not all people who experience hearing loss will develop dementia, the study found that those with severe hearing loss were five times more likely to develop cognitive impairment, and that even mild hearing loss doubled one's risk.
 
“For many years, hearing loss in older adults has been perceived as an unfortunate but inconsequential part of aging,” says Dr. Frank Lin, an assistant professor of otolaryngology and epidemiology at Johns Hopkins, who directed the study. “Our research is now demonstrating that hearing loss doesn’t just affect a person’s quality of life. It may also lead to a decline in cognitive function.”
 
More research needs to be done on the correlation between cognitive decline and hearing loss, but Lin believes that the neurological stress of hearing loss, such as the constant effort required to decode conversations, may ultimately take its toll. "We also know that people with hearing loss tend to avoid socializing," he says, "and that social isolation is a risk factor for dementia."
 
Hearing Loss: Widespread and Widely Ignored

The question of whether early action to treat hearing loss with a hearing aid may help in delaying dementia is “the billion-dollar question,” Lin says, and one that he and his team will address in a new study. “By the year 2050, 1 in 30 Americans are predicted to suffer from dementia, so we’re hoping this new research will help in developing interventions,” he says. “In the interim, we hope to encourage people to take care of their hearing, to take hearing loss seriously, and to be proactive. Hearing loss is a slow, insidious process, and many people don’t realize how bad their hearing has become until they get a hearing test."
 
In fact, hearing loss is the third-most prevalent chronic health problem in older adults, after high blood pressure and arthritis. The U.S. Preventive Task Force recommends that all people ages 50 and over get a hearing test, and that younger people do so if they notice symptoms such as tinnitus (prolonged ringing in the ears). If a test indicates that your hearing is impaired, the task force advises treating it without delay, as you would any other major medical problem.

Typical age-related hearing loss, or presbycusis, is caused by progressive damage to the hair cells of your inner ear. When these hairs are damaged or die, they cannot grow back. Hearing loss can be caused by natural changes in the inner ear, but can be exacerbated by genetics, continued exposure to loud noise, or smoking.

Not all hearing loss is permanent and not all cases require a hearing aid. Some hearing loss is caused by a reaction to aspirin, ibuprofen, or ibuprofen, which can be ototoxic (damaging to the ear), particularly in men. Hearing often improves after a patient stops taking the medicines. Ear infections, injuries, and earwax can also cause reversible hearing loss.

Unfortunately, too many of us put off taking any action on our hearing. “There’s a huge paradox when it comes to treating hearing loss in young people as opposed to older adults," Lin says. "If a 12-year-old’s audiogram shows significant hearing loss, the family will want to begin treatment right away, whereas if you attach that same audiogram to a 62-year-old, people are more apt to accept it as an inevitable part of aging. Most people wouldn’t hesitate to take medication for high blood pressure, yet those same people may balk at getting a hearing aid.”

If you need a hearing aid, get one. An estimated 26.7 million Americans over age 50 have hearing loss and could benefit from a hearing aid, based on research conducted by Lin and his team, but only about 3.8 million of them wear one. The rest hesitate, whether out of denial about their hearing loss, concerns about discomfort, or worries about the cost. What many people may not realize is that today's hearing aids have better sound quality, and are less obvious than previous models. While Medicare generally does not cover the cost of hearing aids, it does cover hearing tests from an audiologist, if prescribed by a physician. Many private insurers do as well. Private Medicare Advantage plans may reimburse some of the cost of hearing aids and replacement batteries. If cost is still a concern, the Starkey Hearing Foundation provides hearing aids for people with low incomes. Call 866-354-3254 or visit the foundation website to learn more. Also, military veterans can qualify for hearing aids at a greatly reduced cost through the U.S. Department of Veterans Affairs.
 
How To Protect Your Hearing
 
Dr. Gordon Hughes, program director, Clinical Trials, at the Division of Scientific Programs at the National Institutes of Health’s Institute on Deafness and Other Communication Disorders, shares these tips for reducing your risk of age-related hearing loss, and preventing existing damage from getting worse:
 
  • Avoid extreme noise. Noise exposure, a leading cause of hearing loss, can be caused by prolonged exposure to any noise over 85 decibels (dB), Hughes says. So you should be aware that an MP3 player at full volume is 100dB; a concert, auto race, or sporting event could be around 110dB; and gunshots or fireworks, around 140dB. “If you can’t avoid prolonged exposure to loud noise," Hughes advises, "wear foam earplugs or earmuffs that fit over the entire outer ear."
  • Quit smoking. “Smoking has been shown to be a risk factor for hearing loss,” Hughes says, because the chemicals in cigarette smoke can affect the hearing mechanisms of both the middle ear and the inner ear. Need another reason to quit? Do it for your kids or grandkids. A 2011 study conducted at the New York University School of Medicine found that exposure to tobacco smoke nearly doubles the risk of hearing loss among teens.
  • Manage your diabetes well. “Both diabetes and high blood pressure can predispose you to developing hearing loss,” Hughes says. A National Institutes of Health study found that hearing loss is twice as common in people who have diabetes than in those who don't. Poor blood-sugar control, over time, can damage the small blood vessels and nerves in the inner ear that assist with hearing. A recent study conducted at Henry Ford Hospital in Detroit found that women between the ages of 60 and 75 with well-controlled diabetes had better hearing than women with poorly controlled diabetes. Insufficient blood flow in the inner ear or related areas of the brain, which can be caused by cardiovascular disease, untreated high blood pressure, or other conditions, can also contribute to hearing loss.
  • Get screened. If you’re 50 or older, or if you're younger but believe that you have experienced hearing loss, make an appointment with an audiologist to get an exam. If you'd like a preview, take this free, quick, and confidential online hearing check first.