Most people can expect to deal with hearing loss in the course of normally long lives. 50% of people in their 70’s suffer from it, as do 80% of people in their 80’s. Unfortunately, besides being troublesome, it appears that hearing loss can have a direct causal effect on dementia, as well as other bad outcomes. (See the table in our post Nine Factors Contributing to Dementia — You Can Manage Them. Hearing loss, at 9%, is the largest factor.)
1,164 participants (average age 73.5) in a 24-year longitudinal study underwent assessments for hearing acuity and cognitive function between the years 1992 to 1996. All of them were followed for up to 24 years with up to five subsequent cognitive assessments at approximately four-year intervals. None used a hearing aid.
Almost half of the participants had mild hearing impairment, with almost 17% suffering moderate-to-severe hearing loss. Those with more serious hearing impairment showed worse cognitive performance at the initial visit. Hearing impairment was associated with greater decline in performance on cognitive tests over time, both for those with mild hearing impairment and those with more severe hearing impairment.
Here are two media articles on the work:
With age comes hearing loss and a greater risk of cognitive decline
How hearing impairment is associated with cognitive decline
Here is the abstract of the original research article:
Hearing impairment and cognitive decline in older, community-dwelling adults.
Similar conclusions arise from a study of 8 years of data from more than 10,000 men. The study compared the effects of hearing loss with measures of subjective cognitive decline, which is changes in memory and thinking that people notice in themselves.
The risk of subjective cognitive decline was 30 percent higher among men with mild hearing loss, compared with those with no hearing loss, while for men with moderate or severe hearing loss, the risk was between 42 and 54 percent higher.
Hearing loss and cognitive decline: Study probes link
Longitudinal study of hearing loss and subjective cognitive function decline in men
In another study that covered over 154,000 adults 50 and older who had health insurance claims, but no evidence of hearing device use, researchers found that untreated hearing loss increased the risk of developing dementia by 50 percent and depression by 40 percent in just five years when compared to those without hearing loss. This study also demonstrated a clear association between untreated hearing loss and not only an increased risk of dementia and depression, but also falls and even cardiovascular diseases.
Here are three media articles on this study:
Hearing Loss Threatens Mind, Life and Limb
Higher risk of dementia and depression with an untreated hearing loss
Hearing Loss in Older Adults Linked to Depression, Dementia Among Other Comorbidities
Here is the original research publication:
Incident Hearing Loss and Comorbidity: A Longitudinal Administrative Claims Study
There is concrete evidence that using hearing aids can slow the rate of cognitive decline, as shown by two recent research studies.
Here is a review discussion of the first research publication on hearing aids:
Evidence that Hearing Aids Could Slow Cognitive Decline in Later Life
First research article:
Longitudinal Relationship Between Hearing Aid Use and Cognitive Function in Older Americans
Here are media articles about the second research publication on hearing aids:
Hearing aids linked to lower risk of dementia, depression and falls
Hearing aids lower the chance of dementia, depression, and falling
Second research article:
Can Hearing Aids Delay Time to Diagnosis of Dementia, Depression, or Falls in Older Adults?
Finally, we note a study, closely related to the “Administrative Claims Study” above, which shows that untreated hearing loss tends to lead to higher health care costs over time. (Users of hearing aids were not considered in the study, so, as yet, one cannot conclude that hearing aid use might lower costs, though that might be a reasonable inference.)
Patients with untreated hearing loss incur higher health care costs over time
Trends in Health Care Costs and Utilization Associated With Untreated Hearing Loss Over 10 Years