The effect of treating hearing loss with hearing aids on plasma biomarkers of Alzheimer's disease and related dementias

BACKGROUND: Though evidence indicates that treating hearing loss with hearing aids (HAs) could reduce dementia risk, the effects on biomarkers of Alzheimer's disease and related dementias (ADRD) remain unknown. METHODS: Observational data from Aspirin in Reducing Events in the Elderly (ASPREE) study participants without dementia and with hearing problems were used. We emulated two target trials to estimate the effect of (1) new HA prescription and (2) the frequency of HA use on plasma ADRD biomarkers after 7 years using targeted maximum likelihood estimation, with multiple imputation for missing data. RESULTS: There was a median of 2842 individuals (mean 75 years, 48% female) across imputed datasets, and 735 new HA prescriptions. Estimated treatment effects were close to null for phosphorylated tau181, neurofilament light chain, glial fibrillary acidic protein, and amyloid beta 42/40. There was little evidence of effect modification (e.g., by apolipoprotein E ε4 genotype). DISCUSSION: In older people with hearing loss, HA prescription and frequency of use had minimal association with levels of ADRD biomarkers.