Racial and ethnic differences in the associations of sensory impairments with cognition in older United States adults

BackgroundSensory impairments are associated with cognitive decline and Alzheimer's disease risk.ObjectiveWe studied how sensory function and cognitive change varied by race/ethnicity in Hispanic, non-Hispanic Black (NHB), and non-Hispanic White (NHW) older US adults.MethodsWe studied 2799 individuals, 57-85 years-old, in the National Social Life, Health, and Aging Project with baseline sensory and follow-up Montreal Cognitive Assessment (MoCA) information from 2005-2016. Hearing was interviewer-rated; vision, smell, taste, and touch were objectively measured. Senses were categorized (poor, moderate, normal); number of poor senses (impairment) was summed. Multivariable linear regressions evaluated the association between sensory impairments and cognition, adjusting for demographic and clinical variables. We tested for differences by race/ethnicity using interaction terms.ResultsHispanic (n = 180) and NHB (n = 509) older adults had higher prevalence of ≥1 sensory impairments and lower cognition scores versus NHW respondents (n = 2110). Having multiple impairments significantly interacted with race/ethnicity such that estimates for the association with cognition was significantly lower for NHB versus NHW respondents (beta = -3.08, 95% CI: -5.14, -1.02; p = 0.004). Interactions were borderline significant for smell, where estimated difference in cognition associated with moderate (β=-0.91, 95% CI: -1.91, 0.10, p = 0.077) and poor (β=-1.33, 95% CI: -2.77, 0.11, p = 0.071) smell was lower for NHB versus NHW participants.ConclusionsOur findings suggest racial/ethnic differences in how strongly sensory impairments predict cognition, especially for number of impairments and possibly smell. Further insight may reduce disparities in cognitive aging.