Informant-based hearing difficulties and the risk for mild cognitive impairment and dementia

Abstract

Background: hearing loss has been associated with mild cognitive impairment (MCI) and dementia. Studies have not assessed whether hearing difficulties (HD) that interfere with daily activities as reported by partners can be a marker for increased risk for cognitive decline and impairment.

Objective: to assess the cross-sectional and longitudinal associations between informant-based HD, which interfere with daily activities and the risk for MCI and dementia.

Methods: the study included 4812 participants without dementia, enrolled in the Mayo Clinic Study of Aging (mean age (SD) 73.7 (9.6) years) with cognitive evaluation and informant-based report on participant's HD that interfere significantly with daily activities at baseline and for every 15 months. Cox proportional hazards models (utilising time-dependent HD status and age as the time scale) were used to examine HD and the risk for MCI or dementia, and mixed-effects models (allowing for random subject-specific intercepts and slopes) were used to examine the relationship between HD and cognitive decline.

Results: about, 981 participants had HD and 612 (12.7%) had prevalent MCI at baseline; 759 participants developed incident MCI and 273 developed incident dementia. In cognitively unimpaired participants at baseline, those with HD had higher risk for MCI (hazard ratio [HR] = 1.29, 95% confidence interval [CI] (1.10, 1.51), P = 0.002; adjusting for sex, years of education). In participants without dementia, those with HD had higher risk for dementia (HR: 1.39, 95% CI, (1.08-1.79), P = 0.011; adjusting sex and education). In individuals with MCI, HD was associated with modestly greater cognitive decline.

Conclusions: informant-based HD was associated with increased risk for MCI and dementia.

Keywords: cohort study; dementia; hearing difficulties; mild cognitive impairment; older people.

Figure 1

Longitudinal association of HD and cognitive performance. In mixed-effects models adjusting for age, sex, education and allowing for random subject-specific intercepts and slopes, CU individuals with baseline HD declined similarly with regards to global cognition z-scores compared to CU without HD (estimated annualised difference −0.001; 95% CI, −0.007 to 0.005; P = 0.86), while slopes in participants with MCI and HD were steeper than in those with MCI but without HD (estimated annualised difference −0.047; 95% CI, −0.064 to −0.030; P = 0.006). Figure derived from mixed-effects models using mean covariate values for age, sex and education, allowing for random subject-specific intercepts and slopes.