Previous research has demonstrated inverse associations between experiences of interpersonal discrimination and telomere length, a marker of cellular aging. Here, we investigate within-race interactions between multiple indices of interpersonal discrimination and sociodemographic characteristics in relation to telomere length in African American and White adults. Participants were from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (Baltimore, Maryland). Ages ranged from 30 to 64 years old and all self-identified as either African American (n = 176) or White (n = 165). Using linear regression, three patterns were observed within African Americans: (1) women reporting greater lifetime burden of discrimination (p = .02), racial (p = .03), or gender (p = .01) discrimination; (2) those with higher socioeconomic status reporting greater lifetime burden (p = .03) or racial discrimination (p = .02); and (3) younger adults reporting greater exposure to multiple sources of discrimination (p = .03) had shorter telomere length. Among Whites, younger and older men reporting greater racial discrimination had shorter and longer telomeres, respectively (p = .02). Findings demonstrate within-race patterns of interpersonal discrimination and cellular aging, which may contribute to racial health disparities.

Objective: Explore interactive relations of lifetime discrimination burden and racial discrimination – chronic stressors among African Americans (AA) – and age with magnetic resonance imaging (MRI)-assessed white matter lesion volume (WMLV), a prognostic indicator of poor clinical brain health outcomes. Methods: AA (N= 71; 60.6% female, mean age = 50) participating in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study underwent quantitative MRI coded for WMLV. Participants self-reported lifetime discrimination burden and racial discrimination approximately five years earlier. Multivariable regression models assessed interactions of linear and quadratic effects of discrimination and age with WMLV adjusted for sex and socioeconomic status. Results: Findings revealed significant interactive relations of age and (1) quadratic, lifetime discrimination burden, B = .05, p = .014, η2partial = .092, and (2) quadratic, racial discrimination, B = .03, p = .001, η2partial = .155 with WMLV. Among older AA, increases in lifetime discrimination burden and racial discrimination were associated with increases in WMLV (p’s < .03); in younger AA, decreasing levels of racial discrimination were related to increases in WMLV (p = .006). Conclusions: Among older AA, as lifetime discrimination burden and racial discrimination increased, so did WMLV. However, in younger AA, decreases in racial discrimination were associated with increased WMLV. Elucidation of complex mechanistic underpinnings, including potentially differential impacts of the acknowledgement versus suppression or underreporting of discriminatory experiences, among AA of different age cohorts, is critical to understanding the present pattern of findings.

There is a growing literature demonstrating a link between lower socioeconomic status (SES) and poorer neuroanatomical health, such as smaller total and regional gray and white matter volumes, as well as greater white matter lesion volumes. Little is known, however, about the relation between SES and white matter integrity. Here we examined the relation between SES and white matter integrity of the brain’s primary cortical regions, and evaluated potential moderating influences of age and self-identified race. Participants were 192 neurologically intact, community-dwelling African American and White adults (mean age = 52 years; 44% male, 60% White, low SES = 52%) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging. Diffusion tensor imaging was used to estimate regional fractional anisotropy (FA) to quantify the brain’s white matter integrity and trace to capture diffusivity. Multiple regression analyses examined independent and interactive associations of SES, age, and race with FA of the frontal, temporal, parietal, and occipital lobes bilaterally. Sensitivity analyses assessed the influence of several biopsychosocial risk factors on these associations. Exploratory analyses examined these relations with trace and using additional SES indicators. Results indicated there were no significant interactions of SES, age, and race for any region. Individuals with low SES had lower FA in all regions, and higher trace in the right and left frontal, right and left temporal, and left occipital lobes. Findings remained largely unchanged after inclusion of sensitivity variables. Older age was associated with lower FA and greater trace for all regions, except for the right temporal lobe with FA. No main effects were found for race in FA, and Whites had higher trace values in the parietal lobes. Novel findings of this study indicate that relative to the high SES group, low SES was associated with poorer white matter integrity and greater diffusivity. These results may, in part, reflect exposures to various biopsychosocial risk factors experienced by those of lower SES across the lifespan, and may help explain the preponderance of cognitive and functional disparities between socioeconomic groups.

County (UMBC) ScholarWorks@UMBC digital repository on the Maryland Shared Open Access (MD-SOAR) platform.

Objective: The present study investigates whether associations between telomere length (TL) and cognitive performance across multiple domains are moderated by poverty status and race. Method: Participants were 325 African American and White urban-dwelling adults (M age = 47.9 years; 49.5% African American; 50.2% female; 48.9% living in poverty) from the Healthy Aging in Neighborhoods of Diversity across the Life Span study. TL was assayed from peripheral blood mononuclear cells using quantitative polymerase chain reactions. Multivariable regression analyses examined interactions of TL, poverty status, and race with performance on the following cognitive tests: Trail-Making Test Parts A and B, Digit Span Forward and Backward, semantic verbal fluency, Brief Test of Attention, Benton Visual Retention Test (BVRT), and California Verbal Learning Test-II total learning, short-delay free recall, and long-delay free recall scores. Analyses adjusted for age, sex, and high school-or-greater educational attainment. Results: Significant three-way interactions of TL × Poverty Status × Race revealed that, among White participants living in poverty, shorter TL was associated with worse performance on Digit Span Forward and Backward (ps<.05). Additionally, significant two-way interactions of TL × Poverty Status revealed that, among all participants living in poverty, shorter TL was associated with worse performance on the Trail-Making Test Part B and the BVRT (ps<.05). Conclusions: TL may be differentially associated with aspects of attention, executive functioning, and memory among individuals living in poverty, who may be uniquely vulnerable to adverse effects of shorter telomeres. Replication of these findings is needed to determine their generalizability.