It is well established that hearing loss and cognitive decline correlate with one another. There is some debate over causation, the degree to which hearing loss might contribute to cognitive decline versus both outcomes arising from the same underlying mechanisms of cell and tissue damage that drive aging. Recent studies strongly suggest that loss of hearing does accelerate cognitive decline, but this doesn't rule out shared contributions to both conditions from underlying processes or a bidirectional relationship of mutual causation.
Hearing loss (HL) of moderate or higher grades is common in older adults with increasing prevalence as people age, rising from 12% at the age of 60 years to over 58% at 90 years. HL in midlife is one of the main potentially modifiable risk factors for dementia. It is estimated that 7% of dementia cases globally could be avoided if this risk factor was eliminated.
Participants from the Brazilian Longitudinal Study of Adult Health were evaluated in three study waves (2008-10, 2012-14, and 2017-19). HL was defined as pure-tone audiometry above 25 dB in the better ear. Cognitive performance was evaluated with six tests related to memory, verbal fluency, and trail-making tests. A global cognitive z-score was derived from these tests. The association between HL and cognitive decline was evaluated with linear mixed-effects models adjusted for sociodemographic, lifestyle, and clinical factors.
Of 805 participants (mean age 51 ± 9 years), 62 had HL. During follow-up, HL was associated with faster global cognitive decline (β = -0.012). In conclusion, HL was significantly associated with a faster rate of global cognitive decline after a median follow-up of eight years in a sample of middle-income country.
Link: https://doi.org/10.1177/13872877251315043
View the full article at FightAging
