Associations of sensory impairments with cognition vary by race in older US adults

Abstract

AbstractBackgroundSensory impairments are associated with increased dementia risk in older adults, but whether such associations vary by race is unknown.MethodWe studied 2,058 participants from the National Social Life, Health, and Aging Project (NSHAP) aged 57 to 85 without cognitive impairment at the time of recruitment. 8% identified as Hispanic, 13% as non‐Hispanic Black, and 76% as non‐Hispanic White. Sensory function in the 5 senses (vision, hearing, smell, taste, touch) was measured by visual acuity, interviewer‐rated hearing, a five‐item smell identification test, a four‐item taste identification test, and touch by single point and 2‐point discrimination. Previously published cut‐points defined poor, fair, and good levels of function. Cognition was measured with a modified version of the Montreal Cognitive Assessment (MoCA) in the same subjects 10 years later. Linear regression models with interaction terms evaluated whether the association between sensory impairments and cognition differed by race/Ethnicity, adjusting for age, sex, and education.Result64.7% of individuals had poor sensory function (≥1 impairment). Hispanic (n = 228) and non‐Hispanic Black (n = 237) older adults were more likely to have ≥1 sensory impairments and to have lower cognition scores compared to non‐Hispanic Whites (n = 1,593). In adjusted models including all participants, fair interviewer‐rated hearing (‐0.68 points, CI:‐1.09,‐0.27), fair smell (‐0.77 points, CI:‐1.14,‐0.41), fair taste (‐0.37 points, CI:‐0.73, ‐0.01), and having multiple sensory impairments (‐0.73 points, CI:‐1.27, ‐0.19) were associated with lower cognition compared to good sensory function/ no impairments. For smell, taste, and touch there were differences by race. The estimated effect of fair smell on subsequent lower cognition was stronger in non‐Hispanic Blacks compared to Whites (‐0.99 points, CI: ‐1.90,‐0.09, p for interaction = 0.03). The estimated effect of poor taste on worse cognition was stronger in non‐Hispanic Whites compared to Hispanics (‐1.42 points, CI: ‐2.62,‐0.22, p for interaction = 0.02). There was a significant association between poor touch and lower cognition in Hispanics but not for other racial groups (‐2.03 points, CI: ‐3.81, ‐0.25, p = 0.03).ConclusionWe found important racial differences in how sensory dysfunction predicts future cognition. Sensory impairments are often modifiable; further insight on these differences may help stimulate efforts to reduce disparities in dementia burden.