Self-Reported Hearing Loss and Longitudinal Cognitive Function in a Cohort Enriched with Risk for Alzheimer's Disease

Abstract

Background: Growing evidence suggests hearing loss is a risk factor for mild cognitive impairment and dementia, but few studies have examined its relationship to sub-clinical cognitive outcomes.

Objective: To investigate the effect of self-reported hearing loss on longitudinal cognitive function in a risk-enriched cohort of clinically-unimpaired, late middle-aged adults.

Methods: 579 participants from the Wisconsin Registry for Alzheimer's Prevention (WRAP) were included. Hearing status was determined via self-reported history of diagnosed hearing loss. Each participant with self-reported hearing loss was age- and sex-matched to two participants who never reported hearing loss using nearest-neighbor matching. Linear mixed-effects models were used to examine associations between self-reported hearing loss and age-related cognitive trajectories with covariates of sex, literacy, and ethnicity, person-level random intercepts and age-related slopes. Cognitive outcomes encompassed measures of speed and flexibility, visuospatial memory, and verbal fluency.

Results: Participants with self-reported hearing loss exhibited significantly poorer performance on a speed and flexibility factor score and single test of psychomotor speed and executive function, relative to participants who never reported hearing loss. There was no association between self-reported hearing loss and visuospatial memory or verbal fluency. Longitudinally, self-reported hearing loss was associated with less rapid decline in speed and flexibility and no difference in rate of decline for any other cognitive measure.

Conclusion: Self-reported hearing loss was associated with poorer speed and flexibility but not with accelerated decline in any domain studied, contrary to previous findings. Further studies involving behavioral auditory measures in this cohort would clarify the robustness of these findings.

Keywords: Alzheimer’s disease; cognition; cognitive impairment; executive function; hearing; hearing loss; longitudinal studies.

Figure 1:

Proportion density plots of baseline age for participants who never reported hearing loss and those who reported hearing loss at any visit, before (A) and after (B) matching.

Figure 2:

Longitudinal cognitive performance by proportion of visits with self-reported hearing loss. Graphs depict age on the x-axis and cognitive performance on the y-axis for the four measures (A-D). Higher scores indicate better performance on all measures. Proportion of visits with hearing loss was modeled as a continuous variable, but estimated slopes for three hearing groups (hearing loss at no visits, half of visits, or all visits) are depicted for simplicity.