Adults younger than 70 years with hearing loss who used hearing aids were less likely to develop dementia over 2 decades compared with those who did not use them, according to a prospective analysis of US community-based data. No such association was observed in adults aged 70 years or older.
led by Lily Francis, MBBS, MPhil, of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at The University of Texas Health Science Center at San Antonio.
During follow-up, 583 patients (20%) developed dementia. Among those who were younger than 70 years at baseline hearing evaluation, patients with hearing loss who used hearing aids had a 61% lower risk of developing dementia compared with those who had hearing loss but did not use hearing aids.
In the same age group, patients without hearing loss had a 29% lower risk of dementia compared with those who had hearing loss and no hearing aids. These associations remained statistically significant following adjustment for age, sex, vascular risk factors, and education level. In patients aged 70 years or older at baseline, hearing aid use was not associated with a statistically significant difference in dementia risk.
The analysis included 2,953 patients from the Framingham Heart Study original and offspring cohorts. All were aged 60 years or older at baseline and did not have dementia. Patients underwent pure-tone audiometry and were classified as having no hearing loss, hearing loss without hearing aids, or hearing loss with hearing aids.
Hearing loss was defined as a pure-tone average of at least 26 decibels in the better ear. Baseline hearing assessments took place from 1977 to 1979 for the original cohort and from 1995 to 1998 for the offspring cohort. Patients were followed for up to 20 years for incident all-cause dementia and diagnosed using standardized criteria.
Study strengths included a large sample size, standardized hearing assessments, and long-term follow-up. Limitations included reliance on a single self-reported measure of hearing aid use without assessing duration or consistency, inability to determine whether early intervention referred to younger age or less severe hearing loss, and lack of control for socioeconomic status beyond educational attainment. Hearing aid users may also have had better access to health care, which could influence dementia risk independently of hearing aid use.
Researchers noted the importance of early intervention for hearing loss to reduce the risk of incident dementia, especially, they noted, because only 17% of patients with moderate to severe hearing loss reported using hearing aids.
Disclosures are available in the published study.
Source: JAMA Neurology
