Relationship of Hearing Loss and Dementia

Abstract

Objective To determine whether baseline hearing loss increases cognitive decline and risk for all-cause dementia in a population of elderly individuals. Study design Longitudinal cohort study Setting Community-based, outpatient Patients Men and women aged 65 years or older without dementia at baseline Intervention(s) All subjects completed the Modified Mini-Mental Status Exam (3MS-R) at baseline and over 3 triennial follow-up visits. Hearing loss (HL) at baseline was based on observation of hearing difficulties during testing or interview. Incident dementia was determined by clinical assessment and expert consensus. Main outcome measure(s) Dementia and 3MS-R score. Results At baseline 4,463 subjects were without dementia, 836 of whom had HL. Of those with HL, 16.3% developed dementia, compared to 12.1% of those without HL (p<0.001). Mean time to dementia was 10.3 years in the HL group vs. 11.9 years for non-HL (Log Rank test p<0.001). In Cox regression analyses controlling for gender, presence of APOE- ε4 allele, education, and baseline age, and cardiovascular risk factors, HL was an independent predictor of developing dementia (Hazard ratio = 1.27, p=0.026 (95% CI = 1.03, 1.56). Linear mixed models controlling for similar covariates showed HL was associated with faster decline on the 3MS-R, at a rate of 0.26 points/year worse than those without HL. Conclusions Elderly individuals with HL have an increased rate of developing dementia and more rapid decline on 3MS-R scores than their non-hearing impaired counterparts. These findings suggest that hearing impairment may be a marker for cognitive dysfunction in adults age 65 and older.

Hearing Loss and Risk of Mild Cognitive Impairment and Dementia: Findings from the Singapore Longitudinal Ageing Study

“…Our results support recent population-based longitudinal studies that demonstrated older persons with HL were more likely to experience accelerated cognitive decline or incident dementia [5,6,7,8]. There is little previous literature investigating the association of HL with MCI, a prodromal stage of dementia that confers a high risk of developing dementia.…”

“…The use of hearing tests such as the pure tone audiogram is difficult in large population studies due to the time required, cost, and subject compliance. Population studies have variously used other methods to report the presence of HL including self-report, difficulty in hearing cognition tests, requirement for an audio amplifier to complete cognition tests, and hearing aid use [7]. We used the whispered voice test as it is a simple hearing test and one of the most accurate available compared to pure tone audiometry, with a reported sensitivity of 72.3% and specificity of 70% in detecting HL of ≥40 dB in the better hearing ear in the local elderly Singaporean population [27].…”

“…A recent meta-analysis reported that cognition is significantly poorer in individuals with untreated HL and remains poorer in those whose HL is treated compared to individuals with normal hearing [4]. HL is consistently shown to be associated with increased risk of developing dementia in older persons of Western populations [5,6,7,8]. There has been little work investigating the relationship between HL and the risk of mild cognitive impairment (MCI), representing a transitional stage between normal healthy ageing and the development of dementia [9].…”

Hearing Impairment and Incident Dementia: Findings from the English Longitudinal Study of Ageing

“…The current study built on previous longitudinal studies conducted in the United States and Wales that found that individuals with moderate and severe hearing loss were at greater risk of developing dementia 6, 7, 12, 22. Six hundred thirty‐nine adults aged 65 and older from the Baltimore Longitudinal Study of Aging were prospectively analysed over 11.9 years 7.…”

The Mouse as a Model for Age-Related Hearing Loss - A Mini-Review

“…Projections in both the US and UK suggest that the number of people affected by ARHL will effectively double by 2031, largely due to an increased lifespan [2] (Action on Hearing Loss http://www.action onhearingloss.org.uk/your-hearing/about-deafness-and-hearing-loss/statistics.aspx). ARHL inevitably causes communication difficulties and is associated with social isolation, depression and reduced physical and cognitive function [3,4]. There is a growing literature on the association between hearing loss and cognitive decline; however, it is unknown whether this link is via common pathological mechanisms or because the lack of auditory input contributes to accelerated cognitive decline [5].…”