The modifying effects of cardiovascular risk factors on the relationship between lifetime discrimination and cognitive function: Study of Healthy Aging in African Americans (STAR)

Abstract

AbstractBackgroundDiscrimination is a root cause of health inequities contributing to the excess burden of cognitive impairment among Black Americans. Using the Study of Healthy Aging in African Americans (STAR) we examined whether the effect of lifetime discrimination on late‐life cognitive decline was magnified by early adulthood cardiovascular risk factors.MethodSTAR enrolled long‐term Kaiser Permanente Northern California members ages 50+ who identify as Black/African American. In early adulthood, participants completed Multiphasic Health Check‐ups (MHC; 1964‐1985) where systolic blood pressure (BP), total cholesterol, and body mass index (BMI) were assessed. A latent class analysis identified groups based on responses to the Major Experiences of Discrimination Scale and gender. Standardized z‐scores for executive function (EF) and verbal episodic memory (VEM) were measured over 3 waves (2018‐2022) using the Spanish and English Neuropsychological Assessment Scales. Linear mixed models with random intercepts and slopes associated latent class with cognitive decline adjusting for age at MHC, age at baseline cognitive assessment, education, and assessment mode (in‐person/telephone). Separate models tested class*cardiovascular risk factor interactions.ResultParticipants (n = 646) averaged 27.7(SD = 7.3) years of age at MHC and 68.5(SD = 8.8) at baseline cognitive assessment (Table 1). Four latent classes were identified: men reporting widespread discrimination (Class‐1men; 12%), women reporting widespread discrimination (Class‐2women; 22%), men and women reporting unfair police treatment (Class‐3police; 17%), and men and women reporting little/no discrimination (Class‐4no_discimination; 49%). Using Class‐4no_discimination as reference, those in Class‐2women had significantly higher baseline EF (β(95% CI):0.18(0.03,0.34)) while Class‐1men (β:0.04(‐0.15,0.23)) and Class‐3police (β:‐0.08(‐0.25,0.09)) did not differ (Figure 1). Class‐2women (β:0.17(0.00,0.33)) had higher baseline VEM compared to Class‐4no_discrimination while Class‐1men (β:‐0.40(‐0.60,‐0.19)) and Class‐3police (β:‐0.27(‐0.46,‐0.09)) had significantly lower (Figure 1). There were no differences in rate of decline. There was a systolic BP*class interaction (p = 0.04) where 5 mm Hg higher systolic BP in early adulthood was associated with worse EF for Class‐3police (β:‐0.07(‐0.12,‐0.02)) compared to Class‐4no_discrimination while Class‐1men and Class‐2women did not differ (Figure 2). This pattern was similar for VEM but non‐significant (interaction p = 0.07). We found no interactions with total cholesterol or BMI.ConclusionFor Black Americans, discriminatory experiences may differentially impact late‐life cognition, and elevated systolic BP in early adulthood may exacerbate this harm.