Association between hearing loss and development of dementia using formal behavioural audiometric testing within the Mayo Clinic Study of Aging (MCSA): a prospective population-based study.

BACKGROUND

Hearing loss has been identified as a potential major modifiable risk factor for developing dementia. This study examined associations between formal behavioural pure-tone and speech audiometry assessed by an audiologist with development of dementia in the Mayo Clinic Study of Aging (MCSA).

METHODS

The MCSA is a prospective population-based study examining the incidence, prevalence, and risk factors of mild cognitive impairment and dementia in Olmsted County, Minnesota, USA. Participants undergo clinical examinations with neuropsychological testing at enrolment and every 15 months. Participants were 50 years or older at enrolment between Nov 29, 2004, and Dec 23, 2019, who underwent formal behavioural audiometric evaluation by an audiologist due to concerns about hearing loss or as a part of annual comprehensive health assessments. Associations of pure-tone average (PTA) and word recognition scores (WRS) with the development of dementia were evaluated using Cox proportional hazards regression with age as the timescale, and associations with changes in cognitive testing scores over time were evaluated using linear mixed-effects models.

FINDINGS

Among 1200 eligible participants, the mean age at enrolment was 79 years (SD 9), 593 (49%) were men, and 207 developed dementia during a mean of 7·0 years (SD 3·7) of follow-up. After adjusting for sex, years of education, smoking status, diabetes, hypertension, apolipoprotein E ε4 carriership, and hearing rehabilitation (defined as hearing aid or cochlear implant use), neither PTA (hazard ratio [HR] per 10-decibels hearing level increase of 0·99 (95% CI 0·89-1·12; p=0·91) nor WRS (HR per 10% decrease of 0·98, 95% CI 0·89-1 ·07; p=0·65) was significantly associated with the development of dementia. However, both PTA and WRS were significantly associated with poorer performance in cognitive testing over time: participants with a PTA higher than 25 decibels hearing level or a WRS lower than 100% had significantly worse declines in cognitive testing scores. Informant-based hearing difficulties assessed by the participant's study partner were significantly associated with the development of dementia (HR 1·95, 95% CI 1·45-2·62; p<0·0001).

INTERPRETATION

In this prospective population-based study, subjective informant-based hearing difficulties were associated with development of dementia, whereas objective measures on formal behavioural audiometry were predictive of poorer performance on cognitive testing over time but not the development of dementia. Other factors related to central processing might potentiate the effects of peripheral hearing loss detected on behavioural audiometric testing.

FUNDING

National Institute of Health, the Alexander Family Alzheimer's Disease Research Professorship of the Mayo Clinic, the GHR Foundation, the Mayo Foundation for Medical Education and Research, the Liston Award, the Schuler Foundation, the Rochester Epidemiology Project medical records linkage system, and the National Institute on Aging.

Informations de copyright

Copyright © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Déclaration de conflit d'intérêts

Declaration of interests RCP has been a consultant for Roche, Biogen, Merck, Eisai, Genentech, and Nestle; receives publishing royalties from Mild Cognitive Impairment (Oxford University Press, 2003) and UpToDate; and receives research support from the US National Institutes of Health. NSR is on the advisory board of Neosensory and receives funding from the National Institute of Health and the National Institute on Aging. MV has received research funding from F. Hoffmann-La Roche and Biogen in the past, consults for F. Hoffmann-La Roche, receives research funding from the National Institutes of Health, and has equity ownership in Abbott Laboratories, Johnson and Johnson, Medtronic, AbbVie, and Amgen. All other authors declare no competing interests.