Hearing aids may lower dementia risk among older adults with hearing loss

Moderate to severe hearing loss was associated with a higher prevalence of dementia among older adults, a research letter in JAMA reported.

However, hearing aids might mitigate this risk, a finding that comes amid new policies that increase accessibility of these devices while lowering costs, according to researchers. This includes the FDA’s ruling to permit the sale of over-the-counter hearing aids in the United States.

Alison R. Huang, PhD, MPH, a senior research associate in the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health, and colleagues noted that research is limited on the association between dementia and hearing loss.

“Previous estimates were vulnerable to selection bias and typically used self-reported data, which may underestimate hearing and dementia and not reflect the true association on a national scale,” they wrote.

To fill the gaps in national estimates, the researchers utilized data on community-dwelling individuals from the National Health and Aging Trends Study. Their analysis included 2,413 participants aged 70 years and older. Among them, 34.38% (n = 769) were aged 75 to 79 years, 53.8% (n = 1,347) were women and 82.34% (n = 1,790) were white.

Huang and colleagues reported that among the participants, the weighted prevalence of dementia was 10.27% (95% CI, 8.9-11.83) overall, and increased with increasing hearing loss severity:

• 6.19% (95% CI, 4.31-8.8) for normal hearing loss;
• 8.93% (95% CI, 6.99-11.34) for mild hearing loss; and
• 16.52% (95% CI, 13.81-19.64) for moderate to severe hearing loss.

The weighted prevalence of hearing loss, meanwhile, was 36.74% (95% CI, 34.67-38.86) for mild hearing loss and 29.79% (95 CI, 27.47-32.22) for moderate to severe hearing loss.

“Participants with moderate to severe hearing loss were more likely to be older, male, and white and to have lower education levels compared with participants with mild hearing loss or normal hearing,” the researchers noted.

Of the 853 participants with moderate to severe hearing loss, hearing aid use (n = 414) was associated with a lower prevalence of dementia compared with no hearing aid use (prevalence ratio = 0.68; 95% CI, 0.47-1).

Huang and colleagues wrote that the findings support public action taken to increase accessibility to hearing aids, “including increased availability of affordable hearing aids and Medicare provision of hearing aids and rehabilitation services.”

The researchers listed several limitations of the study, which included the exclusion of residents in nursing homes and residential care facilities, as well as the cross-sectional design.

Moving forward, “mediation analyses to characterize mechanisms underlying the association and randomized trials to determine the effects of hearing interventions on reducing dementia risk are needed,” the researchers concluded.