Hearing Loss and Dementia: Is there a Connection?

Hearing loss and dementia have many things in common. Both conditions come on slow.. and many people ignore the symptoms until the condition advances. Research now shows that there is a very strong connection between hearing loss and dementia.  Hearing loss is a normal part of aging, dementia is not.

In the Framingham Heart Study.. researchers discovered an association between hearing loss and cardiovascular disease.

Dr.David R.Friedland, a professor of otolaryngology at the Medical College of Wisconsin in Milwaukee in a 2009 paper hypothesized that low-frequency hearing loss could be an early indicator that a patient has vascular problems as the inner ear is “so sensitive to blood flow” that any vascular changes “could be noted earlier here than in other parts of the body.”

A study released by Johns Hopkins and National Institute on Aging researchers suggests individuals that have hearing loss have a significant chance of developing dementia.

Researchers looked into other factors that are associated with risk of dementia:

Diabetes

High blood pressure

Age

Sex

And race.

Dr. Frank Lin MD, PhD, assistant professor in the Division of Otology at Johns Hopkins University School of Medicine explains, hearing loss and dementia were strongly connected. Dr. Lin went on to say “Researchers have looked at what affects hearing loss. But few have looked at how hearing loss affects cognitive brain function. There hasn’t been much crosstalk between otologists and geriatricians. o it’s been unclear whether hearing loss and dementia are related.”

Dr. Lin and his team reviewed data from the Baltimore Longitudinal Study on Aging(BLSA). This study, by the National Institute on Aging, started in 1958. It has followed thousands of men and women over decades with a variety of different medical conditions in thousands of men and women over decades.

A more recent study, published in the February 2013 Archives of Neurology focused on 639 individuals that were part of the Baltimore Longitudinal Study on Aging. They focused on testing the hearing and cognitive abilities between 1990 and 1994. A quarter of the participating individuals were determined to have some hearing loss at the beginning of the study. None of the participant had any form of dementia.

The participating individuals were then closely monitored with examinations every one to two years. Eighteen years later, 2008, 58 of the 639 participants had developed dementia.

The researchers discovered that the participants that had hearing loss at the start of the study were significantly more likely to develop dementia by the end. The participant that started with normal hearing, were less likely to develop dementia.  Those individuals that had different degrees of hearing loss: mild, moderate, and severe increased their chances to develop dementia significantly over time.  Meaning, the more hearing loss that a person had, the higher the likelihood  they had of developing dementia. Health care professionals feel that many delay treating their hearing loss for as long as 20 years.

George Gates, M.D., a hearing expert at the University of Washington in Seattle, who did his own research study has also demonstrated a link between hearing loss and dementia. He explains, “We listen with our ears but hear with our brains. It is simply not possible to separate audition and cognition.”

Because use of hearing aids is often non compliant, or with the advent of hearing aids purchased on line or at discount stores, the follow up is poor at best. Many users do not find satisfaction with the use of hearing aids and stop wearing them.  There are presently over thirty million Americans with impaired hearing. 1 in 30 are predicted to develop some type of dementia by 2050.  Treatment for those with hearing loss, if proven to be helpful, may have a great impact on the development of dementia.

Caregiver tip: Make an audiological exam part of the annual physical. Encourage the use of hearing aids, as this may slow the decline of dementia progression. When mental status exams are given to your family member with dementia, they may not be accurate, because your family member may not hear or understand what is asked. Discuss this with your health care provider.

For more information, go to:

John Hopkins Study