Experiences of Discrimination on Cognitive Function and Aging among the Oldest Old: LifeAfter90 (LA90) Study

Abstract

AbstractBackgroundDiscrimination is a primary cause of health inequities, and racial/ethnic disparities in dementia are well documented. However, it is unclear whether longevity into old age indicates overcoming discriminatory experiences. Using data from the LifeAfter90 (LA90) Study, we examined the impact of major lifetime discrimination on cognitive function and decline in those 90+.MethodLA90 enrolled Asian, Black, Latino, white, and multi‐racial Kaiser Permanente Northern California members who were followed for incident dementia and aged 90+. Discrimination was measured using the Major Experiences of Discrimination Scale. Latent class analysis identified three groups based on responses to the 10‐item scale, gender, and race/ethnicity. Executive function, verbal episodic memory, and semantic memory were assessed every six months with the Spanish and English Neuropsychological Assessment Scales and scores were z‐standardized to baseline. Linear mixed models with random intercepts and slopes associated latent classes of discrimination with cognitive change over 3 waves (mean = 1.2 years). Models adjusted for age, education, cognitive status (normal/mild cognitive impairment‐ accounting for recall bias), practice effects, follow‐up time, and class*time interactions.ResultOur analytic sample of 445 participants had a mean age of 92.7(SD = 2.3) (Table 1). Class‐1 included mostly white men who reported workplace discrimination and had an average of 2 major discrimination experiences. Class‐2 included white women and non‐white participants who reported little/no discrimination averaging 0 experiences. Class‐3 included all non‐white participants who reported a mean of 4 discrimination experiences. At baseline, using Class‐2 as reference, participants in Class‐1 had significantly better executive function (β(95% CI): 0.28(0.03, 0.52) while Class‐3 did not differ (Table 2). Baseline semantic memory was significantly better for Class‐1 (β(95% CI): 0.33(0.07, 0.58)) and significantly worse for Class‐3 (β(95% CI): ‐0.24(‐0.48, ‐0.00)) compared to Class‐2. We found no class differences in baseline verbal episodic memory. Cognition declined over time across all three cognitive domains (β range: ‐0.31 to ‐0.46), but rate of change did not differ significantly by latent class (Table 3).ConclusionAmong the oldest old, inequalities in cognition persist after accounting for experiences of lifetime discrimination. Despite participants’ incredible longevity, experiences of discrimination have an indelible association with cognitive health.