Hearing Loss Is Associated With Regional Brain Amyloid in a Late Middle-Aged Cohort

Investigate the association of hearing loss (HL), measured by pure-tone average (PTA) and word recognition score (WRS) in the better ear, with cerebral amyloid deposition, measured with amyloid positron emission tomography (PET).

Two-hundred twenty-three participants were included. Primary outcomes included whole brain and regional amyloid standardized uptake value ratio (SUVR) on PET. Primary exposures were PTA and WRS. Multivariable linear regression controlling for relevant covariates was used.

Average participant age (SD) was 65.6 (3.8) years and average PTA was 21.0 (8.5) dB. In the fully adjusted model, there was a higher amyloid SUVR difference of 0.024 (p = 0.048) per 10 dB worsening (increase) in PTA in the left temporal region; though only this region reached statistical significance, associations were similar in magnitude and direction across all regions. For every 10% worsening (decrease) in WRS, there was a higher amyloid SUVR difference in the left temporal (β = 0.053, p = 0.018), right temporal (β = 0.055, p = 0.006), left parietal (β = 0.068, p = 0.006), right parietal (β = 0.076, p = 0.001), left cingulate (β = 0.076, p = 0.004), right cingulate (β = 0.088, 9 p = 0.002), and right frontal (β = 0.052, p = 0.035) regions and globally (β = 0.064, p = 0.005).

Worse hearing was associated with higher amyloid in several brain regions on amyloid PET scans and appeared to be due to cases with the most HL and amyloid burden. The reason for these small effect associations, and whether hearing could be causally related to amyloid plaque, requires further investigation.