Lower risk of atrial fibrillation associated with visible greenness within community life circle: Findings from a population-based study

Existing studies have found the health implications of greenness on cardiovascular health, but largely focus on greenspace rather than visible greenness. We aimed to investigate the relationship between visible greenness within the community life circle and atrial fibrillation (AF). Our study included 11,539 permanent residents from a large prospective cohort in a megacity of southern China from 2015 to 2017. We generated 15-minute walking isochrone for each study participant as the community life circle and combined it with green view index (GVI) to estimate corresponding exposure to residential greenness. GVI was calculated utilizing street view images and a fully convolutional neural network tailored for evaluating urban environments. We combined logistic regression model and a doubly-robust approach to explore the relationship between GVI and AF. Mediation analyses were used to assess the mediating role of air pollution, body mass index (BMI) and exercise time on the relationship between GVI and AF. We found that each IQR increase in GVI exposure was associated with a 22.6 % (95 % CI: 8.7 %, 34.1 %) reduction in the risk of AF. The mediation effect of PM₁ on the relationship between GVI and AF was also identified. Higher visible greenness exposure within community life circle was associated with reduced risk of AF among urban residents. Visible greenness within urban community areas should be emphasized as a solution to promote cardiovascular health.