Aging
Associations of Everyday and Lifetime Discrimination with Hippocampal and White Matter Hyperintensity Volumes among Older Black Adults Yodit Goshu* Yodit Goshu Joseph Fong L. Paloma Rojas-Saunero Eleanor Hayes-Larson Maria Glymour Paola Gilsanz Rachel Whitmer Pauline Maillard Kacie Deters Katelyn Mooney Laura Zahodne Ruijia Chen Tanisha G. Hill-Jarrett Courtney Thomas Tobin Elizabeth Rose Mayeda
Discrimination is linked to poor health outcomes, especially for people racialized as Black in the U.S. Few studies have assessed links between discrimination and dementia neuroimaging biomarkers. We aimed to evaluate the effects of discrimination on hippocampal volume and white matter hyperintensity (WMH) volume among older adults racialized as Black. We used data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) and Study of Healthy Aging in African Americans (STAR) cohorts (n=308). Discrimination was measured using the Everyday Discrimination Scale, a 6-item questionnaire with sum of scores ranging from 0-45, and Major Experiences of Discrimination Scale, a questionnaire with 9 binary items (range 0-9). Scores were reverse coded, summed, and categorized (everyday low 0-9, moderate 10-18, high 19+; major experiences low 0-1, moderate 2, high 3+). We fit linear regression models to relate each discrimination measure with hippocampal volume and log-transformed WMH volume, adjusting for age at scan, educational attainment, sex/gender, parental education, southern birth, and total cranial volume. Mean hippocampal volume was 5.9 cm^3 and mean WMH volume was 6.0 cm^3. Everyday and major experiences of discrimination were not associated with hippocampal volumes (everyday high vs. low b = 0.00, 95% CI: -0.21, 0.22; everyday moderate vs. low b = -0.03, 95% CI: -0.18, 0.12; major experiences high vs. low b = -0.05, 95% CI: -0.20, 0.10; major experiences moderate vs. low b = 0.05, 95% CI: -0.14, 0.24). Everyday discrimination, but not major experiences of discrimination, was associated with higher WMH volume (everyday high vs. low b = 0.64, 95% CI: 0.10, 1.18; everyday moderate vs. low b = 0.28, 95% CI: -0.10, 0.66; major experiences high vs. low b = 0.08, 95% CI: -0.30, 0.48; major experiences moderate vs. low b = -0.15, 95% CI: -0.63, 0.34). Our findings suggest that discrimination may contribute to higher WMH volume among Black older adults in the U.S.