The Association Between Early Age‐Related Hearing Loss and Brain β‐Amyloid

Abstract

Objectives/Hypothesis To analyze the association between early audiometric age‐related hearing loss and brain β‐amyloid, the pathologic hallmark of Alzheimer's disease (AD). Study Design Cross‐sectional analysis of a prospective cohort study. Methods A cross‐sectional analysis was performed on 98 participants in a cohort study of hearing and brain biomarkers of AD. The primary outcome was whole brain β‐amyloid standardized uptake value ratio (SUVR) on positron emission tomography (PET). The exposure was hearing, as measured by either pure‐tone average or word recognition score in the better ear. Covariates included age, gender, education, cardiovascular disease, and hearing aid use. Linear regression was performed to analyze the association between β‐amyloid and hearing, adjusting for potentially confounding covariates. Results The mean age ± standard deviation was 64.6 ± 3.5 years. In multivariable regression, adjusting for demographics, education, cardiovascular disease, and hearing aid use, whole brain β‐amyloid SUVR increased by 0.029 (95% confidence interval [CI]: 0.003‐0.056) for every 10 dB increase in pure‐tone average (P = .030). Similarly, whole brain β‐amyloid SUVR increased by 0.061 (95% CI: 0.009‐0.112) for every 10% increase in word recognition score (P = .012). Conclusions Worsening hearing was associated with higher β‐amyloid burden, a pathologic hallmark of AD, measured in vivo with PET scans. Level of Evidence 3 Laryngoscope, 131:633–638, 2021

No Influence of Age-Related Hearing Loss on Brain Amyloid-β

“…Only 27% of participants with HL used HAs, which may have limited power to detect any effect of HA use in this sample. Strengths of this study are that it is the largest sample to date of preclinical older adults with HL ( n = 142; [ 29–32 ]), objective audiometric assessment of HL, objective non-screening cognitive assessment data obtained through visual, not auditory, presentation, and the use of the Centiloid scale to allow comparison across different tracers and sites.…”

“…adults with HL (n = 142;[29][30][31][32]), objective audio-280 metric assessment of HL, objective non-screening 281 cognitive assessment data obtained through visual, 282 not auditory, presentation, and the use of the Centiloid scale to allow comparison across different tracers and sites.The data from this study and three of four others examining the relation between HL and A␤ suggest that indices of A␤ are not increased in older adults with HL. Three initial studies (two imaging, one via autopsy) investigated whether there was an association between HL and A␤, with all reporting no association[30][31][32].…”

Effects of Chronic Tinnitus on Metabolic and Structural Changes in Subjects With Mild Cognitive Impairment

“…Specifically, a longitudinal population study demonstrated that the risk of dementia increased with hearing loss severity for individuals older than 60 years (Lin et al, 2011). In collaboration with this, the worsening hearing was positively correlated with a higher β-amyloid burden, a pathologic biomarker of AD, measured in vivo with PET scans (Golub et al, 2020). Given this, the effects of chronic tinnitus on functional and structural brain changes in subjects with MCI would be different according to levels of hearing loss, but this awaits further confirmation.…”

The Laterality of Early Age-Related Hearing Loss and Brain β-Amyloid

“…To the best of our knowledge, this is the first investigation of the relationship between ear-specific hearing and brain β-amyloid. Our group previously found an association between ARHL overall (defined by hearing in the better ear) and brain β-amyloid (15). Overall, there is no consensus on whether there is a true relationship between ARHL and β-amyloid or other dementia biomarkers such as tau protein.…”