A Multi-Method Study Investigating the Biopsychosocial Mechanisms Linking Racial Discrimination to Type 2 Diabetes Risk and Self-Management Behaviors Among Black Adults

Abstract

INTRODUCTION: In the United States (U.S.), Black adults have a higher incidence of type 2 diabetes (T2D) than White adults and are more likely to die from T2D. Some of the risk factors for T2D include chronic stress; being physically inactive, obese or overweight; living with prediabetes; being older (over 45); and having a family history of the disease. Black Americans have higher levels of exposure to psychological stressors that are rooted in racial discrimination, as exemplified at the height of the COVID-19 pandemic with the murder of George Floyd, and are consequently at an increased risk of developing stress-related illnesses like T2D. Racial discrimination has been historically neglected in the assessment of stress, and the role it plays in the onset and self-management of T2D remains understudied. Additionally, the mechanisms that link racial discrimination and T2D are not clear. METHODS: In this study, the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) data set was used (Waves 1, 3, and 4) to examine and analyze the relationship between racial discrimination-related stress and T2D risk (measured as having a T2D diagnosis). The HANDLS data set was also used to evaluate the mediating effect of diet quality and moderating effect of adaptive coping on the relationship between racial discrimination-related stress and T2D risk. HANDLS is a longitudinal study that consists of a fixed cohort of 3,720 socioeconomically diverse African American and White adults between 30-64 years of age who reside in the Baltimore City area. Research questions were centered on understanding the natural history of disease in the sample, capturing early biomarkers that influence health disparities in prevention and disease mitigation efforts. This dissertation study aimed to: 1) examine and analyze the effect of racial discrimination-related stress on diet quality and T2D risk among a cohort of Black adults 30-64 years of age, and analyze the effect of coping as a buffering effect, while also examining the influence of nativity status (U.S. born vs. foreign-born) on T2D risk; and 2) explore the role of stress, which may stem from experiences of racial discrimination, in the self-management of T2D among Black adults 18 years of age or older living in Prince George’s County, Maryland and the Metro Detroit, Michigan area. Structural equation modeling (SEM) was performed to assess the causal pathways linking racial discrimination-related stress to T2D risk, while semi-structured in-depth interviews (N=17) shed light on the barriers to and facilitators of participant engagement in behavioral activities (e.g., physical activity, dietary patterns, and medication taking). The interviews explored participants’ access to nutritious and culturally appropriate food options in their communities and the methods used to cope with chronic stressors, such as racial discrimination. The interviews, which focused on T2D self-management, directly explored stress stemming from racial discrimination as well as other identified stressors and were conducted to understand the gravity of experiences of racial discrimination. In-depth interviews were conducted until thematic saturation was reached. Those with a clinical diagnosis of T2D were recruited to participate in the interviews via both The Health Advocates In-Reach and Research (HAIR) Program at the Maryland Center for Health Equity and the Healthier Black Elders Center (HBEC) Participant Resource Pool (PRP). RESULTS: Using SEM with survival analysis to assess T2D risk, the direct effect of racial discrimination on T2D risk was positive (coeff: 0.674, p<0.001), meaning increased experiences of racial discrimination were linked to a later T2D diagnosis. Adaptive coping moderated the relationship between racial discrimination-related stress and T2D risk (p<0.001), while diet quality did not mediate the relationship (p = 0.972). As a secondary approach using generalized SEM with a logistic regression framework, more reported experiences of racial discrimination were directly associated with a decreased odds of not developing T2D during the study period (coeff: -1.319; aOR: 0.27; p<0.001; Cohen’s d = -0.73), meaning that increased experiences of racial discrimination were linked to a higher likelihood of T2D development. The direction of the association was expected. Using latent thematic analysis to explore T2D self-management behaviors, six themes were identified: (1) A change in family dynamics influences diet; (2) Standing firm and unshaken; (3) With age comes increased knowledge; (4) Change comes from within; (5) Partnership with healthcare provider; (6) Relying on God and community. In managing T2D, spousal support and familial loss were key drivers of food choices for male participants. Male participants tended to engage in avoidance coping, while female participants endorsed the superwoman schema and the added stress it brings, all of which contributed to changes in dietary habits for some. CONCLUSIONS: Our study demonstrates that increased use of adaptive coping techniques blunts the response to racial discrimination-related stress among those with fewer reported experiences of racial discrimination. Although different measures of racial discrimination have been developed, validated, and widely used, future research should support improved methods of capturing experiences of racial discrimination, as experiences are often suppressed. In this study, the unique combination of semi-structured in-depth interviews and quantitative analyses using secondary data, allowed for a deeper understanding of the mechanisms through which racial discrimination affects diabetes development and diabetes-related complications, helping to close the gap in health disparities for Black Americans. Findings may contribute to the development of future discrimination measurement tools for Black adults. Findings may also be used to encourage knowledge sharing to reinforce advocacy and further support the allocation of resources (e.g., diabetes self-management education and support programs and mobile clinics) to inner city communities.