Importance: Metabolic syndrome (MetS) is a common health condition that predisposes individuals to cardiovascular disease (CVD) and disproportionately affects Black and other racially and ethnically minoritized people. Concurrently, Black individuals also report more exposure to racial discrimination compared with White individuals; however, the role of discrimination in the development of MetS over time and associated mediators in these pathways remain underexplored.
Objective: To evaluate the association between racial discrimination and MetS in rural Black individuals transitioning from late adolescence into early adulthood and to identify potential mediating pathways.
Design, setting, and participants: This longitudinal cohort study included Black adolescents enrolled in the Strong African American Families Healthy Adults (SHAPE) Project between June 2009 and May 2021. Families resided in rural counties of Georgia, where poverty rates are among the highest in the nation. Analyses included 322 of the 500 participants who originally enrolled in SHAPE and who were eligible to participate. Guardians provided information about socioeconomic disadvantage. Analyses were conducted in April 2023.
Exposures: Youths reported exposure to racial discrimination annually from ages 19 to 21 years.
Main outcomes and measures: MetS was the main health outcome and was measured at ages 25 and 31 years. MetS was diagnosed according to the International Diabetes Federation guidelines, which requires central adiposity (ie, waist circumference ≥94 cm for males and ≥80 cm for females) and at least 2 of the 4 additional components: signs of early hypertension (ie, systolic blood pressure ≥130 mm Hg or diastolic blood pressure ≥85 mm Hg); elevated triglyceride levels (ie, >150 mg/dL); elevated fasting glucose level (ie, ≥100 mg/dL); or lowered high-density lipoprotein levels (ie, <40 mg/dL in men and <50 mg/dL in women). At age 25 years, markers of inflammatory activity (ie, soluble urokinase plasminogen activator receptor [suPAR]) and sleep problems were collected to consider as potential mediators.
Results: In 322 participants (210 [65.2%] female) ages 19 to 21 years, more frequent exposure to racial discrimination was associated with higher suPAR levels (b = 0.006; 95% CI, 0.001-0.011; P = .01) and more sleep problems at age 25 years (b = 0.062; 95% CI, 0.028-0.097; P < .001) as well as a 9.5% higher risk of MetS diagnosis at age 31 years (odds ratio [OR], 1.10; 95% CI, 1.01-1.20; P = .03). Both suPAR (b = 0.015; 95% CI, 0.002-0.037) and sleep problems (b = 0.020; 95% CI, 0.002-0.047) at age 25 years were significant indirect pathways. No significant interactions between sex and discrimination emerged.
Conclusions and relevance: This study suggests that racial discrimination in late adolescence is associated with MetS among Black young adults through biobehavioral pathways. Thus, health interventions for MetS in Black adults will need to contend with sleep behaviors and inflammatory intermediaries as well as address and reduce exposure to racial discrimination to narrow disparities and promote health equity.