Hearing loss and cognition in the mid-to-late life transition

TL;DR

This study finds that hearing loss in midlife is linked to lower cognitive performance, suggesting the connection between hearing and cognition starts earlier than previously thought.

Contribution

The study demonstrates that the association between hearing loss and cognitive decline can be observed in midlife, not just later in life.

Findings

Speech-range hearing loss was associated with lower scores on all cognitive tests.

High-frequency hearing loss was also linked to reduced cognitive performance, except for a borderline result on one test.

Most cases of hearing loss were mild, yet still correlated with cognitive decline.

Abstract

Hearing loss is associated with cognitive decline in later life, but few studies have established whether this association emerges earlier in midlife. We evaluated the cross-sectional association between audiometric hearing loss and cognition in individuals spanning ages 53-65 years. We studied 1,486 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study at a mean age of 61.2 (SD: 3.6), with 58.4% female, 46.4% Black, and 53.6% White. Hearing loss was defined as a pure tone average (PTA) threshold ≥25dB for speech (500-4000 Hz) and high (4000-8000 Hz) frequencies in the better hearing ear. Cognition was measured with the Montreal Cognitive Assessment (MoCA), digit symbol substitution test (DSST), and the Rey Auditory Verbal Learning Test delay recall score (RAVLT). Linear regression models estimated mean differences and 95% confidence intervals (CIs) for the associations between hearing loss in each frequency range and separate cognitive tests, adjusting for age, sex, education, race, health care access, diabetes, prevalent cardiovascular disease, stroke, hypertension, depression, body mass index, and smoking. Hearing loss (11% prevalence) in the speech detection range was associated with lower cognition in all tests (MoCA: -1.31 [95% CI:-1.81,-0.82]; DSST: -2.59 [-5.05,-0.14]; RAVLT: -0.69 [-1.23,-0.15]). High frequency hearing loss (43% prevalence) was also associated with lower cognition in (MoCA: -0.85 [-1.18, -0.52]; DSST: -2.82 [-4.43, -1.23]; and borderline associated with RAVLT: -0.32 [-0.67, 0.03]). Most hearing loss was mild. These findings in a population-based sample suggest that the associations between hearing loss and cognition may be detectable by midlife.