With Age Comes Hearing Loss and a Greater Risk of Cognitive Decline

Scott LaFee wrote . . . . . . . . .

Hearing impairment is a common consequence of advancing age. Almost three-quarters of U.S. adults age 70 and older suffer from some degree of hearing loss. One unanswered question has been to what degree hearing impairment intersects with and influences age-related cognitive decline.

In a new study, researchers at University of California San Diego School of Medicine report that hearing impairment is associated with accelerated cognitive decline with age, though the impact of mild hearing loss may be lessened by higher education.

The findings are published in the Journal of Gerontology: Series A Medical Sciences.

A team of scientists, led by senior author Linda K. McEvoy, PhD, professor in the departments of Radiology and Family Medicine and Public Health, tracked 1,164 participants (mean age 73.5 years, 64 percent women) in the longitudinal Rancho Bernardo Study of Healthy Aging for up to 24 years. All had undergone assessments for hearing acuity and cognitive function between the years 1992 to 1996 and had up to five subsequent cognitive assessments at approximately four-year intervals. None used a hearing aid.

The researchers found that almost half of the participants had mild hearing impairment, with 16.8 percent suffering moderate-to-severe hearing loss. Those with more serious hearing impairment showed worse performance at the initial visit on a pair of commonly used cognitive assessment tests: the Mini-Mental State Exam (MMSE) and the Trail-Making Test, Part B. Hearing impairment was associated with greater decline in performance on these tests over time, both for those with mild hearing impairment and those with more severe hearing impairment.

However, the association of mild hearing impairment with rate of cognitive decline was modified by education. Mild hearing impairment was associated with steeper decline among study participants without a college education, but not among those with higher education. Moderate-to-severe hearing impairment was associated with steeper MMSE decline regardless of education level.

“We surmise that higher education may provide sufficient cognitive reserve to counter the effects of mild hearing loss, but not enough to overcome effects of more severe hearing impairment,” said McEvoy.

Degree of social engagement did not affect the association of hearing impairment with cognitive decline. “This was a somewhat unexpected finding” said first author Ali Alattar. “Others have postulated that cognitive deficits related to hearing impairment may arise from social isolation, but in our study, participants who had hearing impairment were as socially engaged as those without hearing loss.”

The findings, said the authors, emphasize the need for physicians to be aware that older patients with hearing impairments are at greater risk for cognitive decline. They also emphasized the importance of preventing hearing loss at all ages, since hearing impairment is rarely reversible. One important way to protect hearing, they said, is to minimize loud noise exposure since this is the largest modifiable risk factor for hearing impairment.

Source: UC San Diego


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Exploring the Connection between Hearing Loss and Cognitive Decline

Hearing loss affects tens of millions of Americans and its global prevalence is expected to grow as the world’s population ages. A new study led by investigators at Brigham and Women’s Hospital adds to a growing body of evidence that hearing loss is associated with higher risk of cognitive decline. These findings suggest that hearing loss may help identify individuals at greater risk of cognitive decline and could provide insights for earlier intervention and prevention.

“Dementia is a substantial public health challenge that continues to grow. There is no cure, and effective treatments to prevent progression or reverse the course of dementia are lacking,” said lead author Sharon Curhan, MD, MSc, a physician and epidemiologist in the Channing Division for Network Medicine at the Brigham. “Our findings show that hearing loss is associated with new onset of subjective cognitive concerns which may be indicative of early stage changes in cognition. These findings may help identify individuals at greater risk of cognitive decline.”

Curhan and colleagues conducted an eight-year longitudinal study among 10,107 men aged ?62 years in the Health Professionals Follow-up Study (HFPS). They assessed subjective cognitive function (SCF) scores based on responses to a six-item questionnaire administered in 2008, 2012 and 2016. SCF decline was defined as a new report of at least one SCF concern during follow-up.

The team found that hearing loss was associated with higher risk of subjective cognitive decline. Compared with men with no hearing loss, the relative risk of cognitive decline was 30 percent higher among men with mild hearing loss, 42 percent higher among men with moderate hearing loss, and 54 percent higher among men with severe hearing loss but who did not use hearing aids.

Researchers were interested to see if hearing aids might modify risk. Although the found that among men with severe hearing loss who used hearing aids, the risk of cognitive decline was somewhat less (37 percent higher), it was not statistically significantly different from the risk among those who did not use hearing aids. The authors note that this may have been due to limited power or could suggest that if a difference truly exists, the magnitude of the effect may be modest.

The authors also note that the study was limited to predominantly older white male health professionals. This allowed for greater control of variability but further studies in additional populations would be helpful. In addition, the study relies on self-reported hearing loss and subjective measures of cognitive function. In the future, the team plans to investigate the relationships between self-reported hearing loss, change in audiometric hearing thresholds, and changes in cognition in women using several different assessment measures.

“Whether there is a temporal association between hearing loss and cognitive decline and whether this relation is causal remains unclear,” said Curhan. “We plan to conduct further longitudinal studies of the relation of hearing loss and cognition in women and in younger populations, which will be informative.”

Source : Science Daily

Portable Music Players Tied to Hearing Loss in Kids

Lisa Rapaport wrote . . . . . . . .

Children who listen to music through headphones may be at greater risk of noise-related hearing loss, a Dutch study suggests.

Researchers examined hearing test results for 3,316 children ages 9 to 11. They also asked parents about hearing complaints from their children, how often kids used portable music players and how high they typically set the volume.

Overall, 443 children, or 14 percent, had at least some difficulty hearing at high frequencies. High frequency hearing loss, especially in younger people, is often caused by noise exposure.

Regardless of how long they wore headphones or how high they set the volume, kids who used portable music players just one or two days a week were more than twice as likely to have hearing loss as children who didn’t use the devices at all.

“Although we cannot conclude from this study that music players caused these hearing losses, it shows that music exposure might influence hearing at a young age,” said lead study author Dr. Carlijn le Clercq of Erasmus University Medical Center in Rotterdam.

“This is important, because hearing loss is irreversible and thus has lifelong consequences,” le Clercq said by email.

More than nine in 10 older children and teens use some type of portable music player – often a smartphone or tablet – for education and recreation, researchers note in JAMA Otolaryngology-Head and Neck Surgery.

With noise-related hearing loss, sounds can seem muffled or distant and people may hear ringing in their ears. This can sometimes be temporary, happening after a loud concert, but it can become permanent with repeated exposure to noise.

In the current study, 1,244 children, or about 40 percent, never used portable music players. Another 19 percent used portable music players once or twice a week, and about 8 percent used them at least three times weekly.

Most of the kids didn’t have any hearing-related symptoms. Even among children with high frequency hearing loss, only about 7 percent reported symptoms “sometimes” or “often.”

The study wasn’t a controlled experiment designed to prove whether or how portable headphone use might directly cause hearing loss in kids. Some younger children may develop high frequency hearing loss as a result of ear infections, especially when infections are chronic.

Another limitation of the study is that researchers lacked data on portable music player use and hearing-related symptoms for roughly one-third of the study participants.

Still, the results suggest that parents need to be more vigilant about how children use headphones, and how often, said Kevin Franck director of audiology for Massachusetts Eye and Ear and Harvard Medical School in Boston.

“Parents should limit use of a portable music player,” Franck, who wrote a commentary accompanying the study, said by email. It’s too loud if parents can hear it, he said.

Headphones also are not the only way that children may develop hearing loss, noted Colleen Le Prell, an audiology researcher at the University of Texas at Dallas who wasn’t involved in the study. Live concerts, band practice, hunting, power tools, lawn mowers, dirt bikes, mopeds, and other motorized equipment can also create enough exposure to loud noise to potentially damage kids’ hearing, she said by email.

“Limiting music player use should be considered as part of an overall safe listening strategy,” Le Prell added.

Whenever children may be exposed to loud noise, “hearing protection should be provided, and should include ear plugs marketed for musicians, ear muffs, or conventional ear plugs as appropriate for the sound source,” Le Prell advised.

Source: Reuters

Healthy Diet May Lower Risk of Hearing Loss in Women

Hearing loss affects approximately 48 million Americans. Some evidence suggests that diet may influence risk of hearing loss. Previous studies have looked at how specific nutrients affect risk, but the relation of overall diet and risk of developing hearing loss was unclear. In a new study, researchers from Brigham and Women’s Hospital examined the relation between three different diets and risk of developing hearing loss: The Alternate Mediterranean diet (AMED), Dietary Approaches to Stop Hypertension (DASH), and the Alternative Healthy Eating Index-2010 (AHEI-2010) in 70,966 women in the Nurses’ Health Study II who were followed for 22 years, and found that eating a healthy diet is associated with a lower risk of acquired hearing loss in women. Results are published in the Journal of Nutrition on May 11.

“Interestingly, we observed that those following an overall healthy diet had a lower risk of moderate or worse hearing loss,” said Sharon Curhan, MD, an epidemiologist in the Channing Division of Network Medicine at BWH, and first author of the study. “Eating well contributes to overall good health, and it may also be helpful in reducing the risk of hearing loss.”

In this longitudinal study, researchers collected detailed information on dietary intake every four years and found that women whose diets most closely resembled the AMED or DASH dietary patterns had an approximately 30 percent lower risk of moderate or worse hearing loss, compared with women whose diets resembled these dietary patterns the least. Moreover, findings in a sub-cohort of over 33,000 women for whom detailed hearing-related information had been collected suggest that the magnitude of the reduced risk may be even greater than 30 percent, and may also pertain to the AHEI-2010. The AMED diet includes extra virgin olive oil, grains, legumes, vegetables, fruits, nuts, fish and moderate intake of alcohol. The DASH diet is high in fruits and vegetables and low-fat dairy, and low in sodium. The AHEI-2010 diet has common components with AMED and DASH.

Assessment of hearing loss was based on self-report. Researchers say further research in additional populations is warranted.

Source: Brigham and Women’s Hospital


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Cochlear Implants: A Different Kind of ‘Hearing’

Your elderly uncle is hard of hearing and has a difficult time understanding conversation—so much so that he’s feeling frustrated and left out. His hearing aids aren’t helping much.

Your one-year-old daughter was diagnosed with severe hearing loss in both ears, and you’re worried about her ability to learn and understand speech. How will she learn to communicate?

For both of these cases, a cochlear implant may be an option.

What are cochlear implants? Who uses them and why? And how does the U.S. Food and Drug Administration (FDA) play a role? The cochlea is the part of the inner ear that contains the endings of the nerve which carries sound to the brain. A cochlear implant is a small, electronic device that when surgically placed under the skin, stimulates the nerve endings in the cochlea to provide a sense of sound to a person who is profoundly deaf or severely hard of hearing.

“A severe to profound hearing loss in both ears prevents a person from understanding speech and communicating in everyday conversations. Cochlear implants can increase hearing and communication abilities for people who don’t receive enough benefit from traditional hearing aids,” says Srinivas Nandkumar, Ph.D., chief of the Ear, Nose and Throat (ENT) Devices Branch at FDA.

How Does It Work?

A cochlear implant consists of an external part that sits behind the ear and an internal part that is surgically placed under the skin. Usually, a magnet holds the external system in place next to the implanted internal system. The FDA has approved cochlear implants for use by individuals aged one year and older.
Here’s how it works:

  • A surgeon places the cochlear implant under the skin next to the ear.
  • The cochlear implant receives sound from the outside environment, processes it, and sends small electric currents near the auditory nerve.
  • These electric currents activate the nerve, which then sends a signal to the brain.
  • The brain learns to recognize this signal and the wearer experiences this as “hearing.”

“A cochlear implant is quite different from a typical hearing aid, which simply amplifies sound,” says Nandkumar. “Using one is not just a matter of turning up the volume; the nerves are being electrically stimulated to send signals and the brain translates and does the rest of the work.” Moreover, cochlear implant wearers need to undergo intensive speech therapy to understand how to process what they are hearing.

Cochlear implants don’t restore normal hearing, says Nandkumar. But depending on the individual, they can help the wearer recognize words and better understand speech, including when using a telephone.

Does Age Matter?

According to the National Institute on Deafness and other Communication Disorders (NIDCD) at the National Institutes of Health (NIH), for young children who are deaf or severely hard-of-hearing, using a cochlear implant while they are young exposes them to sounds during an optimal period to develop speech and language skills. Several research studies have shown that when these children receive a cochlear implant at a relatively young age (for example, at 18 months) followed by intensive therapy, they tend to hear and speak better than those who receive implants at an older age.

But adults and older children who have acquired severe to profound hearing loss after they have acquired speech can also do very well with an implant, partly because they are post-lingual (that is, already have learned to speak a language). “At that point, a person has to get used to the fact that what he hears sounds differently and more ‘machine-like’ than it did when he had more hearing,” Nandkumar says. “Whereas someone who was profoundly deaf at birth will adapt at a very early age to a cochlear implant and the way in which it processes sound.”

Conversely, people who are deaf since birth and have not gotten implants until they are a bit older (for example, 8 years of age) may not derive as much benefit from cochlear implants.

FDA Regulation of Cochlear Implants

Before manufacturers can bring a new cochlear implant to market, they must submit studies and data to FDA scientists, who will review the information for safety and effectiveness. Cochlear implants are designated as Class III devices, meaning they receive the highest level of regulatory scrutiny. This is because they are surgically implanted near the brain, which increases health risk. Other risks, while minimal, include injury to the facial nerve, meningitis , perilymph fluid leak (fluid from the inner ear leaks through the hole created to place the implant), and dizziness or vertigo.

The Future of Cochlear Implants

Scientists continue to look for ways to improve cochlear implants and how they function once implanted. For example:

  • Companies are developing more sophisticated strategies that help to minimize background noise and increase the noise-to-sound ratio, helping the user to better focus and understand speech.
  • Hearing science researchers also are looking at the potential benefits of pairing a cochlear implant in one ear with either another cochlear implant or a hearing aid in the other ear.

“A cochlear implant won’t restore hearing the way that eyeglasses can fully restore vision,” Nandkumar says. “But companies are developing increasingly sophisticated processing strategies that can reduce background noise and increase the signal-to-noise ratio, in an effort to improve the quality of speech the wearer hears.”

Source: U.S. Department of Health and Human Services