Mediation of physical activity and sedentary behavior on the relationship between neighborhood greenness and cardiovascular outcomes

Abstract

Objectives Neighborhood greenness has been associated with cardiovascular outcomes, with physical activity commonly suggested as a key behavioural mediator. However, whether sedentary behaviour also mediates this association remains unclear. Although it has been recognised as a critical factor for cardiovascular outcomes, limited studies investigated the association between neighborhood greenness and sedentary behaviour. This study investigated whether physical activity and sedentary behaviour serve as potential mediators in the relationship between neighborhood greenness and cardiovascular outcomes. Study design A cross-sectional, population-based study using national survey data and geographic information system (GIS) metrics. Methods Data from the 2020 Korea National Health and Nutrition Examination Survey (KNHANES) (N = 6133) were linked with neighborhood greenness metrics from national landcover maps. Structural equation modelling was used to evaluate whether domain-specific physical activity, by intensity (vigorous and moderate) and context (work-related, leisure-purposed, and commuting), and sitting time showed significant indirect associations between neighborhood greenness and cardiovascular outcomes. Results Neighborhood greenness was significantly associated with reduced sitting time (p < .001), and lower sitting time was negatively associated with diagnosis of hypertension (p < .001), hyperlipidemia (p = .007), and stroke (p < .001). In the structural equation modelling analyses, sedentary time showed significant indirect associations between greenness and three of the cardiovascular outcomes examined. No comparable indirect associations were observed for the physical activity domains. Contrary to our hypothesis, most domains of physical activity were associated neither with neighborhood greenness nor cardiovascular outcomes. Conclusions These cross-sectional findings suggest that sedentary behaviour was consistently associated with the relationship between neighborhood greenness and cardiovascular outcomes. Place-making strategies that address sedentary behaviour may complement those that promote physical activity.