Community design and hypertension: Walkability and park access relationships with cardiovascular health.

ABSTRACT

BACKGROUND: There is an increased literature focusing on the role of the built and natural environments in preventing hypertension. However, very few studies have quantitively analyzed specific pathways through which urban form affects blood pressure levels. OBJECTIVES: To examine how features of the built and natural environments relate to hypertension and the mediating role of transportation and leisure walking and body mass index in this relationship. METHODS: We examined the association between neighbourhood walkability and park availability with hypertension through generalized linear models in two independent population cohorts. One Cohort was 22,418 adults (My Health My Community) and the other cohort was 11,972 adults (BC Generations Project). We employed a path analysis modelling approach to explore the presence and significance of mediating factors that may contribute to any association between walkability or park availability and hypertension. This study intentionally employed walkability measures enforced through municipal zoning and subdivision regulations legally underpinned by health, safety, and welfare. All models were adjusted for socioeconomic and other characteristics where data were available. RESULTS: Our analysis of two population-based Canadian cohorts consistently found that higher levels of walkability and park accessibility were both associated with significantly lower odds of self-reported hypertension, especially for lower income individuals. Mediation analysis showed that obesity accounted for 50% and 52.9% of the total effect of walkability and park accessibility on hypertension, respectively. DISCUSSION: We suggest an integrated population health approach that considers multimorbidity as a result of exposure to car-dependent areas and the lack of green spaces. Longitudinal research is needed to document causal effects of built and natural environments on hypertension.