Examining the Combined Estimated Effects of Hearing Loss and Depressive Symptoms on Risk of Cognitive Decline and Incident Dementia
Danielle S. Powell, Willa D. Brenowitz, Kristine Yaffe, Nicole M. Armstrong, Nicholas S. Reed, Frank R. Lin, Alden L. Gross, Jennifer A. Deal
Abstract
OBJECTIVES: Late-life depression is a comorbidity that may co-occur in older adults with hearing loss-each has prevalent and independent modifiable risk factors for dementia. METHODS: Using data from 1,820 Health, Aging and Body Composition study participants (74 ± 2.8 years, 38% Black race), we compared the hearing loss-dementia/cognitive decline relationship between those with normal hearing/mild hearing loss and those with moderate or greater hearing loss. Using linear mixed-effects and Cox proportional hazard models, we investigated if the associations between hearing loss and cognitive decline or dementia (Modified Mini-Mental State [3MS] Examination and Digit Symbol Substitution Test [DSST]) differed by the presence or absence of depressive symptoms. Depressive symptoms were defined as Center for Epidemiologic Study-Depression scale 10 ≥10 at one or more visits from Years 1-5. Algorithmic incident dementia was defined using medication use, hospitalizations, and cognitive test scores. Audiometric hearing loss was measured at Year 5 and categorized as normal/mild versus moderate or greater hearing loss. RESULTS: Having both hearing loss and depressive symptoms (vs. having neither) was associated with faster rates of decline in 3MS Examination (β = -0.30; 95% confidence interval [CI]: -0.78, -0.19) and DSST (β = -0.35; 95% CI: -0.67, -0.03) over 10 years of follow-up. Having both hearing loss and depressive symptoms (vs. neither) was associated with increased risk (hazard ratio [HR]: 2.91; 95% CI: 1.59, 5.33 vs. HR: 1.54; 95% CI: 1.10, 2.15 hearing loss only and HR: 2.35; 95% CI: 1.56, 3.53 depressive symptoms only) of incident dementia in multivariable-adjusted Cox proportional hazards models. DISCUSSION: Comorbid conditions among hearing-impaired older adults should be considered and may aid in dementia prevention and management strategies.