Examining the Complex Legacy of Structural Racism in Shaping Neighborhood Contexts and Racial Disparities in Allostatic Load: Analyses from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) Study

Abstract

In the United States, non-Hispanic Blacks (NHBs) experience shorter life expectancy than non-Hispanic whites (NHWs). This dissertation utilizes multi-level theories and models to examine historic redlining and subsequent neighborhood conditions as contributors to contemporary demographic differences in allostatic load (AL), a measure of chronic stress, using data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study.

Chapter 1 describes the theoretical frameworks and reviews literature pertinent to the central research questions.

Chapter 2 examines associations between Home Owners Loan Corporation (HOLC) score and AL, whether HOLC scores mediate racial disparities in AL, and whether neighborhood socioeconomic status (nSES) mediates associations between HOLC score and AL. Current residents in areas with more redlining had higher AL scores, reflecting higher physiological responses to chronic stress. Associations were stronger for those aged 55-64 compared to those between 35 and 44, and for NHWs compared to NHBs. HOLC scores explained associations between race and AL, and neighborhood deprivation mediated associations between HOLC score and AL. Together, these findings suggest that HOLC scores are associated with contemporary AL and explain contemporary racial inequities in AL. The effects of HOLC on AL are explained by nSES.

Chapter 3 examines: a) associations between four measures of (nSES) and AL over time and variations by age, race, sex, and household poverty; b) whether these associations remain significant after accounting for physical activity; and c) whether neighborhood perceptions mediate relationships between nSES and AL over time. NDI and neighborhood poverty were associated with AL. Those associations were more positive for individuals aged 65 and older, whites, and women. Associations between nSES and AL were not explained by physical activity (PA) or neighborhood perceptions.

Chapter 4 examines whether: a) the association between neighborhood racial composition (nRC) and AL over time varies by race, sex, and age; b) these associations are mediated by ethnic discrimination, perceived neighborhood environment, or density of neighborhood social institutions; c) nRC mediates associations between HOLC score and AL; and d) nRC mediates associations between HOLC score and nSES. No significant association between nRC and AL was observed, with no variations by race or age. Increases in percent Black was positively associated with AL for females but not males. The non-significant association between nRC and AL was not mediated by perceived ethnic discrimination, perceived neighborhood social environment, or the density of social institutions. Percent Black mediated associations between HOLC score and AL for females but not males and mediated associations between HOLC score and nSES. Together, these findings suggest that nRC is not in and of itself a predictor of AL: Rather, it is on the pathway explaining associations between HOLC score and AL for women, and between HOLC score and some indicators of nSES.

Together, these findings illuminate lasting impacts of historic redlining, a manifestation of structural racism, on contemporary racial inequities in AL, a marker of chronic stress associated with multiple disease outcomes. These associations remain robust after accounting for multiple behavioral and psychosocial indicators, and are significantly explained by the patterning of nSES and nRC. They are consistent with a body of research highlighting the importance of public health interventions that address the lasting impacts of financial divestment from historically redlined and racially segregated neighborhoods in order to address contemporary racial inequities in health.