Nearly One Third of Dementia Cases Tied to Hearing Loss

TOPLINE:

Audiometry-measured hearing loss in older adults accounted for up to 32% of incident dementia cases over 8 years in new research, significantly larger than previously reported estimates. Investigators found larger dementia prevalence estimates in people aged 75 years or older, women, and White individuals, whereas self-reported hearing loss was not associated with dementia risk.

METHODOLOGY:

• This prospective cohort study included nearly 3000 participants from the ARIC Neurocognitive Study with no dementia at baseline who underwent a hearing assessment at follow-up visit 6 (mean age, 75 years; 59% women; 78% White individuals).
• Hearing loss was assessed objectively using pure tone audiometry and subjectively using self-reports. Audiometric hearing loss overall was defined as a pure tone average ≥ 26 dB in the better-hearing ear, whereas mild hearing loss was defined as 26-40 dB and moderate or greater as > 40 dB.
• The primary outcome was the calculation of population attributable fraction (PAF), defined as the maximum proportion of dementia cases in a population that could be attributed to hearing loss.
• About 66% of participants had audiometric hearing loss, whereas 37% had self-reported hearing loss. Total follow-up duration was 8 years (2011-2019).

TAKEAWAY:

• The PAF of incident dementia from any degree of audiometric hearing loss was 32% (95% CI, 11%-47%). In comparison, past studies have shown US estimates of dementia attributable to any measured hearing loss between 2% and 19%.
• The estimates were similar between severity levels, with PAFs of 16.2% vs 16.6% from mild vs moderate or greater hearing loss.
• Moreover, a greater proportion of dementia cases attributed to any hearing loss was found in adults aged ≥ 75 years vs younger people (PAFs, 31% vs 22%), women vs men (31% vs 24%), and White vs Black participants (28% vs 23%).
• Self-reported hearing loss was not associated with a significant increase in dementia risk.

IN PRACTICE:

“This cohort study suggests that treating hearing loss might delay dementia for a large number of older adults. Public health interventions targeting clinically significant audiometric hearing loss might have broad benefits for dementia prevention,” the investigators wrote.

They added that future studies should consider that “self-reporting may underestimate hearing-associated dementia risk.” 

SOURCE:

This study was led by Emily Ishak, Columbia University Irving Medical Center, New York City. It was published online on April 17 in JAMA Otolaryngology-Head & Neck Surgery.

LIMITATIONS:

This study’s generalizability was limited owing to the inclusion of only self-identified Black and White adults. Classifying dementia using hospital and death records may have led to reduced sensitivity toward including milder cases, and a potential survivor bias may have influenced the findings. Additionally, information about appropriate hearing aid use, fit, and compliance was unavailable; and the cumulative effects of hearing loss on the risk for dementia were not assessed.

DISCLOSURES:

The ARIC Neurocognitive Study was funded by the National Institutes of Health. Several investigators reported receiving grants from and having ties with various sources. Full details are provided in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.