Age-related hearing impairment—a risk factor and frailty marker for dementia and AD

Age-related hearing impairment (ARHI, also known as presbycusis) is potentially a reversible risk factor for dementia and Alzheimer disease (AD). Social isolation, loneliness, poor verbal communication, and cognitive reserve depletion might causally link ARHI with cognitive impairment. ARHI is an important frailty marker, and several factors related to physical frailty could be associated with cognitive impairment. Such factors include inflammatory markers and vascular factors, which might also directly contribute to ARHI. Randomized controlled trials of potential interventions, and larger population-based studies, could facilitate further understanding of the interplay between cognitive impairment, ARHI and frailty in older age. Deficits in both peripheral hearing and central auditory processing (CAP) can contribute to ARHI. Impairments in peripheral hearing and CAP have been linked to accelerated cognitive decline, incident cognitive impairment and AD; moreover, CAP dysfunction is common in mild cognitive impairment (MCI) and AD. Assessment of CAP dysfunction in people with ARHI might, therefore, aid identification of older individuals with increased risk of MCI and AD.