Hearing Loss Linked to Dementia and Alzheimer’s Disease

On April 7, 1989, in the 261 volume of The Journal of the American Medical Association, five American scientists published a paper “Relationship of Hearing Impairment to Dementia and Cognitive Dysfunction in Older Adults“. The authors demonstrated an association between hearing impairment and dementia. Since then, more research in this area has been conducted at numerous leading US and world universities. More recently, the relationship between a hearing impairment and Alzheimer's disease has been confirmed. The February 14, 2011 bulletin by the AARP (American Association of Retired Persons) carried the article by Elizabeth Agnvall “Hearing Loss Linked to Dementia. Even a mild hearing loss doubles the risk “. Excerpt reads:

“Adults with hearing loss are significantly more likely than adults with normal hearing to develop dementia, according to a new study out today from researchers at John's Hopkins and the National Institute on Aging. The study -- which finds the greater the hearing loss, the higher the risk – may open a new avenue of research into dementia and Alzheimer's disease.

Man and woman in the study who experienced severe hearing loss were five times more likely to develop dementia than those with normal hearing. But even mild hearing loss doubled the risk of dementia.”

A new study published in the February 2011 issue of ARCHIVES OF NEUROLOGY (Vol. 68) confirmed what a lot of physicians who deal with hearing loss and dementia had suspected before: adults with hearing loss have a greater chance of developing dementia, and this risk increases as their hearing impairment worsens.

“This work suggests that there is a strong predictive association between hearing loss as an adult and the likelihood of developing cognitive decline with aging.”

According to study lead author Dr. Luigi Ferrucci, Chief of the U.S. National Institute on Aging Longitudinal Studies Section. The “COMMENT“ part of this paper states as follows:

“In this study, hearing loss was independently associated with all-cause dementia after adjustment for sex, age, race, education, diabetes, smoking, and hypertension, and our findings were robust to multiple sensitivity analyses. The risk of all-cause dementia increased log linearly with hearing loss severity, and for individuals older than 60 years in our cohort, more than one third of the risk of incident all cause dementia was associated with hearing loss.”

“According to several major studies, older adults with hearing loss are more likely to develop Alzheimer's disease and dementia, compared to those with normal hearing. Further, the risk escalates, as person's hearing loss grows worse. Those with mild hearing impairment are nearly twice as likely to develop dementia compared to those with normal hearing. The risk increases three-fold for those with moderate hearing loss, and five-fold for those with severe impairment.“

And also:

“In response to these findings, further studies found that hearing aids can delay, or prevent, dementia and Alzheimer's disease by improving patients' hearing. Further, treating hearing loss with hearing aids can reduce many Alzheimer's symptoms for people with the disease.”

Should you require more information, we will be happy to provide people interested in this area of research with copies of the papers, articles, used for this issue of our newsletter as well as any new studies results published.

Alicja and Janusz Tobola from Metro Hearing Clinic Mississauga and Scarborough

 905 273 7717