Racial Discrimination and Telomere Length in Midlife African American Women: Interactions of Educational Attainment and Employment Status

Abstract

Background: Over the life course, African American (AA) women have faster telomere attrition, a biological indicator of accelerated aging, than White women. Race, sex, age, and composite socioeconomic status (SES) modify associations of institutional racial discrimination and telomere length. However, interactions with everyday racial discrimination have not been detected in AA women, nor have interactions with individual socioeconomic predictors.

Purpose: We estimated statistical interaction of institutional and everyday racial discrimination with age, education, employment, poverty, and composite SES on telomere length among midlife AA women.

Methods: Data are from a cross-section of 140 AA women aged 30-50 years residing in the San Francisco Bay Area. Participants completed questionnaires, computer-assisted self-interviews, physical examinations, and blood draws. Adjusted linear regression estimated bootstrapped racial discrimination-relative telomere length associations with interaction terms.

Results: Racial discrimination did not interact with age, poverty, or composite SES measures to modify associations with telomere length. Interactions between independent SES variables were nonsignificant for everyday discrimination whereas institutional discrimination interacted with educational attainment and employment status to modify telomere length. After adjusting for covariates, we found that higher institutional discrimination was associated with shorter telomeres among employed women with lower education (β = -0.020; 95% confidence interval = -0.036, -0.003). Among unemployed women with higher education, higher institutional discrimination was associated with longer telomeres (β = 0.017; 95% confidence interval = 0.003, 0.032). Factors related to having a post-high school education may be protective against the negative effects of institutional racism on cellular aging for AA women.

Keywords: African Americans; Aging; Educational status; Employment; Telomeres; Women’s Health.

Fig. 1.

Relative telomere length (RTL) distribution among African American Women’s Heart & Health Study (AAWHHS) participants (N = 140). Participant RTL was considered “standard” if within one standard deviation of the mean, “short” if below one standard deviation of the mean, “long” if above one standard deviation of the mean.

Fig. 2.

Interaction plots of the adjusted estimates for relative telomere length for institutional racial discrimination (EOD) and age, educational attainment, employment status, and poverty among African American Women’s Heart & Health study participants (N = 134). The 5-level ordinal EOD categories represent increasing lifetime exposure to institutional racial discrimination; never (<9), once (9–16), 2–3 times (17–24), 4–5 times (25–32), and 6 or more times (33–40). Nonparallel lines provide evidence of statistical interaction.