Is Work-Related Hearing Loss Associated With Dementia? Evidence From a High-Risk Population.

Abstract

Background: Age-related hearing loss is associated with increased dementia risk. We examined the association between hearing loss and dementia in a population at high risk for hearing loss from occupational noise exposures.

Methods: We conducted cross-sectional and longitudinal analyses using logistic regression and interval-censored Cox models using data from the Building Trades National Medical Screening Program (BTMed), from inception in 1996 through March 2024. Hearing loss was defined as a speech-frequency pure-tone average ≥ 20 decibels (dB) in the better ear and categorized as mild (20-34 dB), moderate (35-49 dB), moderately severe (50-64 dB), or severe to complete (≥ 65 dB). Dementia was defined using criteria from medical history, physical exams, and medication data across all medical screening examinations.

Results: The study included 44,000 exams in 24,958 BTMed participants; 54.6% had hearing loss. Hearing loss was strongly associated with dementia prevalence (211 cases, p < 0.001), with prevalence increasing by severity. Cross-sectional analysis found a significant association between hearing loss ≥ 20 dB and dementia (adjusted odds ratio = 1.88, 95% confidence interval (CI) = 1.15-3.07). In longitudinal analysis, a Cox model adjusted for confounders estimated a hazard ratio of 1.60 (95% CI = 0.99-2.59, p-trend = 0.0928) for incident dementia.

Discussion: Cross-sectional results support an association between occupational hearing loss and dementia, consistent in direction with findings for age-related hearing loss; longitudinal estimates were not significant but were directionally similar. If confirmed in other high-risk cohorts with repeated audiometry, these findings underscore the potential for hearing conservation and hearing loss rehabilitation in dementia prevention.