Hearing aid (HA) prescription was not associated with meaningful improvements in memory or executive function in older adults with moderate hearing loss but was linked to a lower long-term risk for dementia.

Results of a large observations study of nearly 2800 older adults showed overall cognition scores during 7 years of follow-up were similar between adults who did and did not receive a prescription for HAs. However, the 7-year risk for cognitive impairment was 15% lower for those with HA prescriptions, and the risk for dementia was 33% lower.

Although treating hearing loss with HAs may have limited influence on age-related cognitive change, the link with lower risk for dementia was “striking,” the investigators noted.

However, “further studies are needed to understand the ways [HAs] may support memory, thinking, and brain health overall,” study investigator Joanne Ryan, PhD, Monash University, Melbourne, Australia, said in a release.

The findings were published online on January 14 in Neurology.

A Significant Risk Factor

In 2017 and in a 2020 update, The Lancet commission on dementia prevention, intervention, and care named hearing impairment as one of the most significant risk factors for dementia.

However, as reported by Medscape Medical News, previous studies assessing HAs’ role in affecting cognition and/or dementia have shown mixed results.

For the current study, investigators assessed data from 2777 Australian participants aged 70 years or older (mean age, 75 years; 52% men; 98% White) from the ASPREE study.

At baseline, all participants were dementia-free and had moderate hearing impairment.

Questionnaires were used to measure new HA prescriptions (n = 664) and frequency of use. Semiannual assessments over 7 years measured cognition.

The primary outcome was overall cognition score, which combined the following tests from the ASPREE cognitive battery: the Modified Mini-Mental State Examination, the Hopkins Verbal Learning Test-Revised (for learning and memory), the Symbol Digit Modalities Test, and the Controlled Oral Word Association Test (for language and executive function).

Secondary outcomes included a dementia diagnosis or the presence of cognitive impairment, which was defined as a composite of dementia and cognitive decline.

No Impact on Cognition

Results showed that the mean difference in overall cognition scores at year 7 between those with HA prescriptions and those without was insignificant at 0.03.

The investigators noted that this finding “provides class III evidence” that the prescribing of HAs did not substantially change cognitive scores in this particular population.

“Similarly, there was little evidence in the overall cognition score under initiation of different frequencies of HA use,” they wrote.

Ryan added that most of the study participants had good cognitive health at baseline, which may have reduced the potential for later cognitive improvement with HAs.

In contrast, the adjusted estimated 7-year risk for dementia was 5% in those with HA prescriptions vs 7.5% in those without the prescriptions (risk ratio [RR], 0.67), and the 7-year risk for cognitive impairment was 36.1% vs 42.4% (RR, 0.85). Additionally, the risk for each of these outcomes “were inversely associated with the frequency of HA use,” the investigators wrote.

The authors cautioned that the findings may reflect residual confounding rather than a true treatment effect and added that longer-term randomized and observational studies would be “a valuable next step.”

The research was funded by the National Institutes of Health, the National Institute on Aging, the Australian Government, and the Monash University. Two of the investigators reported several financial disclosures, which are fully listed in the original article. The other researchers reported no relevant financial relationships.