Hearing impairment is associated with cognitive decline, brain atrophy and tau pathology

Abstract

AbstractBackgroundThe association between hearing impairment and Alzheimer’s disease (AD) and the mechanisms involved remain unclear.MethodsSurvival analyses were performed in 66,577 participants from the UK Biobank to investigate whether hearing impairment is associated with an increased risk of AD. The association of hearing status with cognitive function, brain structure and CSF proteins were explored in cross‐sectional, longitudinal, and mediation analyses across the UK Biobank (n = 165,550), Chinese Alzheimer’s Biomarker and Lifestyle (CABLE, n = 867), and Alzheimer’s Disease Neuroimaging Initiative (ADNI, n = 802).ResultsHearing impairment was associated with an increased risk of AD over 11 years of follow‐up (HR 1.80, 95%CI 1.50‐2.15). Poor hearing status was associated with worse cognitive function in cross‐sectional and longitudinal studies. Moreover, hearing impairment was significantly related to lower volume of the temporal cortex, hippocampus, amygdala, inferior parietal lobe, precuneus and orbitofrontal cortex, to lower integrity of white matter tracts, and to a higher level of CSF tau protein. Mediation analyses showed that brain structure and CSF tau partly mediated the association between hearing impairment and cognitive decline.ConclusionHearing impairment is a risk factor for AD, and is associated with brain structure, tau pathology, and cognitive decline.