Rethinking 15-min walkable neighborhoods for healthy aging: evidence from cardiovascular health in Shanghai's older adults.

Interventions targeting chronic diseases through urban built environments have gained increasing attention due to their potential population-level health benefits. However, empirical evidence on the relationship between built environment features and cardiovascular health among older adults remains limited, particularly in ultradense Asian cities experiencing rapid population aging. This study analyzed fine-scale built environment data to delineate 15-min walkable neighborhoods around 2,579 stroke emergency visits among adults aged 60 to 80 in Shanghai. Participants were classified as survivors or non-survivors based on outcomes during their initial hospitalization, serving as a proxy for cardiovascular health status. Using binary logistic regression, we examined associations between neighborhood environmental characteristics and cardiovascular outcomes. Results indicated that higher residential building density and proximity to major roads were significantly linked to poorer cardiovascular health, whereas greater neighborhood greenness, measured by the Normalized Difference Vegetation Index (NDVI), was associated with better outcomes, especially within socioeconomically disadvantaged neighborhoods. Streetscape features such as visible sky and greenery were positively correlated with better cardiovascular health in more affluent areas. Additionally, a U-shaped relationship emerged between the proportion of residential land use and cardiovascular outcomes in disadvantaged communities. These findings provide nuanced, context-specific insights into how fine-scale built environment factors relate to cardiovascular health among aging urban populations, offering valuable implications for land use planning and healthy urban design.