People with hearing loss who started using hearing aids in their 60s had less dementia risk for up to two decades, data from the Framingham Heart Study suggested.

Over up to 20 years of follow-up, participants ages 60 to 69 who used hearing aids had a 61% lower risk of incident dementia than their counterparts with hearing loss who didn’t use a hearing aid (HR 0.39, 95% CI 0.17-0.89, P=0.03), reported Sudha Seshadri, MD, of the University of Texas Health Science Center at San Antonio, and colleagues.

People in their 60s with no hearing loss also had a lower risk of dementia over time compared with those who had hearing loss and no hearing aid (HR 0.71, 95% CI 0.54-0.95, P=0.02), Seshadri and co-authors wrote in a JAMA Neurologyopens in a new tab or window research letter.

The analysis may be the first to identify that reduced risk depends on early intervention for hearing loss, the researchers noted.

“This study of Framingham participants suggests that managing hearing loss during midlife — improving hearing with the use of a hearing aid — could help protect the brain and reduce risk of dementia,” Seshadri told MedPage Today.

Several studies have found that hearing aids may have a protective benefitopens in a new tab or window against dementia but they mainly have focused on people over age 70. The ACHIEVE trialopens in a new tab or window showed that a hearing intervention could reduce cognitive change over 3 years in older adults at increased risk for cognitive decline.

Earlier this year, data from two large U.K.-based cohort studies opens in a new tab or window identified a modest association between midlife hearing impairment and dementia risk over decades-long follow-up periods.

Seshadri and colleagues evaluated 2,953 dementia-free participants ages 60 or older in the Framingham Heart Studyopens in a new tab or window original and offspring cohorts. All participants underwent pure-tone audiometry and were followed for incident dementia for up to 20 years.

The researchers defined pure-tone average as the mean of hearing thresholds at frequencies of 0.5, 1.0, 2.0, and 4.0 kHz. They defined hearing loss as a pure-tone average of 26 dB or higher hearing loss in the better ear with self-reported hearing aid use. They used DSM-V criteria to determine all-cause dementia and adjusted findings for age and sex.

Mean age was 69 and 59% were women. Over the follow-up period, 583 people developed incident all-cause dementia; of these, 245 people were younger than age 70 at hearing assessment.

Significant interactions with age emerged. There was no association between hearing aid use and incident dementia in people ages 70 and older, but there was one in younger participants. The relationship between hearing aid use and dementia persisted in people ages 60 to 69 after adjusting for 10-year vascular risk and education level.

Limitations included the study’s reliance on a binary response to a question about hearing aids which couldn’t capture how extensively hearing aids were used, Seshadri and co-authors acknowledged. The researchers also couldn’t control for socioeconomic status beyond education level and pointed out that hearing aid users may have better access to healthcare. The findings were observational and causality can’t be established.

“Only 17% of individuals with moderate to severe hearing loss use hearing aids,” Seshadri and colleagues observed. “Our study underscores the importance of early intervention for hearing loss to reduce risk of incident dementia.”

Originally appeared on MedPage Today