ARTICLE SUMMARY: The impact of hearing impairment and hearing aid use on progression to mild cognitive impairment in cognitively healthy adults: An observational cohort study
A research article published in February of 2022 detailed its findings on how hearing loss and the use of hearing aids may have an impact on mild cognitive impairment (MCI) in cognitively healthy adults. MCI is described as an early stage of memory loss or other cognitive loss, like difficulty with language or visual/spatial perception in people who can otherwise still perform normal day-to-day activities. It refers to a condition that isn’t quite as severe as dementia, but has a greater impact than the usual age-related changes in brain function.
Hearing loss and cognitive impairment often happen together, which leads us to question whether hearing loss leads to cognitive impairment, or the other way around. In many ways, it’s a chicken-or-the-egg question, which came first? This is why researchers have been studying the effect of hearing aids and cochlear implants, and whether or not their use has a positive effect on one’s brain function.
The study was divided in three scenarios, and they each had a goal:
- To study how hearing impairment affects cognitive function in healthy individuals. This was done by investigating the impact of hearing loss as it progresses from normal health to MCI.
- To investigate the link between hearing aid use, the incidence of MCI, and cognitive deterioration. This was done by measuring the association between hearing aid use and the individual’s progression from healthy to MCI.
- To compare how long it takes for MCI to present itself between people with normal hearing and those with hearing loss using hearing aids. This was done by comparing the difference in MCI diagnosis between individuals experiencing no hearing loss, to those with hearing loss using hearing aids.
In broad terms, the study found that individuals suffering from hearing loss were at a risk of developing MCI at a much higher rate when compared to those with normal hearing or those using hearing aids. Let’s break down the results.
|RESULTS: Scenario 1||RESULTS: Scenario 2||RESULTS: Scenario 3|
|Those experiencing hearing loss were at a higher risk of developing MCI compared to those with normal hearing.||The use of hearing aids was associated with a much lower risk of a healthy person developing MCI.||When comparing healthy individuals to those with a hearing impairment using hearing aids, there was no difference in how long it took MCI to be diagnosed.|
Now, in many research studies there is a risk of confounding. Confounding is when a study is unintentionally impacted by the effects of an unknown factor that could lead to a distortion of the facts. Because of this, researchers conducted a sensitivity analysis to counteract confounding to ensure the accuracy of their findings. With the sensitivity analysis completed, researchers confirmed the primary findings of their research, meaning even with confounding taken into consideration, the results were the same: that “hearing impairment is independently associated with accelerated cognitive decline and a higher risk of incident MCI.”
Simply put, the use of hearing aids is linked to lower rates of cognitive decline, and a reduced risk of MCI. In fact, hearing aid users have more than a 50% lower risk of developing MCI compared to those not using them. The study showed no differences between individuals with no hearing loss, and those with hearing loss using hearing aids when it comes to developing MCI. This leads researchers to believe that the use of hearing aids could reduce the cognitive decline associated with hearing loss.
Why is this important? Because of the main takeaway: This study supports the notion that access to hearing health care may be an effective strategy to proactively prevent dementia.