Age-Related Trajectories of Memory Function in Middle-Aged and Older Adults with and without Hearing Impairment

To examine age-related trajectories of memory function associated with hearing status and to explore potential confounding by sociodemographic, physiological, and behavioral factors in that link.

A national representative sample of Taiwanese adults ≥50 years with and without hearing impairment in 1996 (n = 4,707) were interviewed every 3-4 years until 2007. Cross-sectional and prospective associations between hearing impairment and memory function were determined using multilevel modeling.

In bivariate analyses, hearing impairment was associated not only with poor memory function but also with sociodemographic, behavioral and self-rated health status and chronic conditions. These factors, however, did not confound the relationship of hearing impairment with the level or rate of change in the modified Rey Auditory Verbal Learning Test (m-RAVLT) score - hearing impairment increased the age-related differences in the intercept of the memory function by 25.6%, and that the association was significantly greater in older people than in younger people, but hearing impairment was not associated with the slope of the cognitive trajectory over time.

Hearing impairment and the m-RAVLT score at any point in time may have partially combined pathologic mechanisms with age. The vascular risk covariates we considered might also share the etiological pathways and be part of important prevention strategies for guarding against age-related memory decline in the future.