Hearing Impairment Associated with AD Risk, Cognitive Decline, Brain Structure Changes, and Tau Pathology

A study presented at the 2023 meeting of the Alzheimer’s Association International Conference (AAIC) found that hearing impairment is a risk factor for the development of Alzheimer disease (AD) and is associated with cognitive decline, brain structure, and tau pathology.

To identify an association between AD and hearing impairment, survival analyses were conducted for 66,577 participants from the UK Biobank database cohort. Results revealed that hearing impairment increases the risk of developing AD with a hazard ratio of 1.80 (95% CI, 1.50-2.15). In addition, cross-sectional, longitudinal, and mediation analyses of data obtained from 165,500 participants from the UK Biobank, 867 patients from the Chinese Alzheimer’s Biomarker and Lifestyle (CABLE) study, and 802 participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) study were performed. These analyses examined associations between hearing status and cognitive function, cerebrospinal fluid (CSF) proteins, and brain structure over 11 years of follow up.

Hearing impairment was found to be associated with worse cognitive function and reduced volume of specific brain regions, including the hippocampus, temporal cortex, inferior parietal lobe, amygdala, orbitofrontal cortex, and precuneus. Associations also were identified between hearing impairment and higher CSF tau protein levels and decreased white matter tract integrity. The identified associations between hearing impairment and worse cognitive function were partly mediated by changes in brain structure and CSF tau levels.

The results of this study were presented by Jin-Tai Yu, MD, PhD, from the Huashuan Hospital of Fudan University in Shanghai, China.