Residential green space and incidence of cardiovascular disease: Evidence from a nationwide population-based study.

Residential green space may be an environmental determinant of cardiovascular disease (CVD); however, longitudinal evidence based on structural measures of green space in nationwide populations remains limited in South Korea. We investigated the association between the proportion of residential green space and incident CVD, with particular attention paid to variation by degree of urbanization. Data from the National Health Insurance Service-National Sample Cohort, including 321,999 participants without prior CVD who underwent health examinations between 2010 and 2012, were analyzed. Residential green space, quantified as the proportion of park area at the municipal level, was categorized into quartiles. Incident CVD was identified using ICD-10 codes for acute myocardial infarction (I21-I23), heart failure (I50), and cerebrovascular diseases (I60-I64). Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) with adjustments for demographic, socioeconomic, behavioral, and clinical factors. A higher proportion of residential green space was associated with a lower risk of incident CVD. Individuals in the highest quartile was had a 17% lower risk of CVD compared with the lowest quartile (aHR = 0.83, 95% CI: 0.78-0.88), with a significant dose-response relationship across quartiles (p for trend <0.001). Among all area types, the inverse association between green space and CVD risk was statistically significant in the highest quartile, with a more consistent dose-response pattern observed in metropolitan areas. These findings suggest that greater residential green space contributes to a lower CVD risk, supporting the role of green environments in public health strategies for CVD prevention.