The association of perceived discrimination with dementia risk in Black older adults

Abstract

Introduction: Non-Hispanic Black, compared to non-Hispanic White, older adults are at increased risk for dementia. This may be due partly to greater exposure to psychosocial stressors, such as discrimination; however, few studies have examined this association.

Methods: We examined the association of perceived discrimination (e.g., everyday, lifetime, and discrimination burden) with dementia risk in 1583 Black adults co-enrolled in the Atherosclerosis Risk in Communities (ARIC) Study and the Jackson Heart Study (JHS). Perceived discrimination (defined continuously and using tertiles) was assessed at JHS Exam 1 (2000-2004; mean age ± SD:66.2 ± 5.5) and related to dementia risk through ARIC visit 6 (2017) using covariate-adjusted Cox proportional hazards models.

Results: Associations of perceived everyday, lifetime, and burden of discrimination with dementia risk were not supported in age-adjusted models or demographic- and cardiovascular health-adjusted models. Results were similar across sex, income, and education.

Discussion: In this sample, associations between perceived discrimination and dementia risk were not supported.

Highlights: In Black older adults perceived discrimination not associated with dementia risk. Younger age and greater education linked to greater perceived discrimination. Older age and less education among factors associated with dementia risk. Factors increasing exposure to discrimination (education) are also neuroprotective.

Keywords: dementia risk; discrimination; macro level factors; older Black adults.

Figure 1.

Study timeline. Measures of discrimination were assessed during Exam 1 of the JHS. Following the assessment of discrimination, participants completed comprehensive cognitive testing during visits 5 and 6 of the ARIC study. Prior to ARIC visit 5, dementia was ascertained using the International Classification of Diseases, Ninth Revision (ICD-9) and diagnostic codes from death certificates. At ARIC visit 5, participants with suspected dementia received a modified version of the Clinical Dementia Rating scale (CDR), and their informant received a Functional Activities Questionnaire (FAQ). For participants who did not attend visit 5, dementia was diagnosed using the CDR and FAQ measures, the Telephone Interview for Cognitive Status–Modified (TICSm), and ICD-9 hospital discharge diagnosis codes or diagnostic codes from death certificates. Between visits 5 and 6, participants were administered the Six-item screener (SIS) and the Ascertain Dementia 8-item Informant Questionnaire (AD8) annually. Throughout the ARIC study, continuous hospital surveillance was also used to captured ICD-9 and hospital discharge diagnosis codes or diagnostic codes from death certificates to identify dementia. Brief cognitive assessment (visits 2 [1990–1992] and 4 [1996–1998]): Digit symbol substitution, Delayed word recall, Semantic fluency. Comprehensive cognitive assessment (visit 5 [2011–2013]): Mini-Mental State Examination (MMSE), Digit Span backward, Digit symbol substitution, Trail making part A, Delayed word recall, Logical Memory II, Word fluency test (FAS), Animal fluency, Boston naming test, Clock reading. Comprehensive cognitive assessment (visit 6 [2016–2017]): Mini-Mental State Examination (MMSE), Digit symbol substitution, Delayed word recall, Logical Memory I and II, Incidental learning, Word fluency test (FAS), Animal naming, Boston naming test, Trail Making parts A and B.

Figure 2.

Participant Exclusions. Participant exclusion flowchart. ARIC: Atherosclerosis Risk in Communities; JHS: Jackson Heart Study. Analytic sample reflects the number of participants used for each respective analysis in the present study.

Figure 3.

Association between Discrimination and Incident Dementia. Hazard ratio (HR) and 95% confidence interval (CI) for the association of discrimination with incident dementia. Participants who reported no discrimination were used as a reference group. Participants who reported discrimination levels greater than “None” were divided into ascending tertiles based on level of reported discrimination. Model 1was adjusted for age. Model 3 was adjusted for age, sex, education, income status, hypertension, diabetes, stroke, coronary heart disease status/history, and cigarette smoking status. Sample sizes for Models 1 and 3 are as follows: Everyday discrimination (n = 1,394); Lifetime discrimination (n = 1,369); Burden of Discrimination (n = 1,092). Results for model 2, which adjusted for age, sex, education, and income status, are presented in the Supplementary Tables 4–6.

Figure 4.

Kaplan-Meier Curves for Time-to-Dementia Onset by Discrimination. Figure depicts the Kaplan-Meier curves for time to dementia onset by a) everyday discrimination, b) lifetime discrimination, and c) burden of discrimination. For all analyses, participants who reported no discrimination were used as the reference group. Participants who reported discrimination levels greater than “None” were divided into ascending tertiles based on level of reported discrimination.