Understanding Neighborhood Physical and Social Environments in Relation to Blood Pressure Changes in the Multi-Ethnic Study of Atherosclerosis.

Abstract

Neighborhood environments have been associated with a variety of health outcomes, but much of the existing research has relied on cross-sectional data or used non-specific measures of the neighborhood. This dissertation uses longitudinal data on specific measures of neighborhood physical and social environments from the Multi-Ethnic Study of Atherosclerosis (MESA) to explore how neighborhood environments change over time and how specific neighborhood environments affect blood pressure. The first analysis investigated how changes in four survey-based measures of neighborhood environments (availability of healthy food, walking environment, social cohesion, and safety) were patterned by area socio-demographic characteristics (area socioeconomic status [SES], percentage of Black residents, and percentage of Hispanic residents). After adjusting for individual-level characteristics, we found that lower SES neighborhoods and neighborhoods with more minority residents generally had poorer physical and social environments, and that these disparities were stable or increasing over time. The second analysis used proportional hazards models to explore neighborhood physical and social environments in relation to incident hypertension using survey-based measures of neighborhood environments and GIS-based measures of the density of favorable food stores and recreational activity resources. After adjustment for individual and neighborhood-level covariates, one standard deviation higher healthy food availability was associated with a 12% lower rate of hypertension (HR = 0.88, 95% CI 0.82-0.95); other neighborhood environment measures were not related to incidence of hypertension. The third analysis used linear mixed models to describe how neighborhood survey- and GIS-based measures of physical and social environments were associated with baseline levels and changes over time in systolic blood pressure (SBP). Using imputed values for SBPs influenced by antihypertensive medication use, we found that better neighborhood food and physical activity environments were associated with lower SBPs at baseline, while better neighborhood social environments were associated with higher SBPs at baseline. There was little evidence that neighborhood environments affected SBP trajectories over time. The results of this dissertation add new evidence on the way that neighborhood socio-demographic characteristics relate to neighborhood physical and social environments, and how those environments affect cardiovascular health; these results may shape interventions to reduce social disparities in health.