Associations of residential greenness with peripheral and central obesity in China

Abstract

BackgroundObesity is a well-known risk factor for public health. Recent studies found that greenness exposure may protect against obesity. However, the accumulated evidence on associations of greenness-obesity is inconsistent and most of them are from developed countries. ObjectivesThis study aimed to evaluate the associations of greenness exposure with indicators of peripheral and central obesity. MethodsThis cross-sectional study was based on a Chinese national Sub-Clinical Outcomes of Polluted Air (SCOPA) prospective cohort across 15 provinces, and 5849 participants with average age of 64.7 were included. Surrounding greenness was estimated with the Enhanced Vegetation Index (EVI), which was calculated at each participant's residential addresses within a 250 m buffer. Weight, height and waist circumference (WC) were measured, and body mass index (BMI) and the waist-to-height ratio% (WHtR%) were calculated based on those measurements. The relationships between EVI and obese outcomes were explored using multiple linear regression and logistic regression models. ResultsNon-linear associations were observed between EVI and obese indicators. Participants living in Quartile 3 benefited more than in Quartile 4 compared to the lowest quartile (Quartile 1) of greenness. For peripheral obesity, participants living in Quartile 3 of EVI250m had 0.86 kg/m2 (β −0.86, 95% CI: −1.10, −0.61) lower BMI, and 46% (OR 0.54, 95% CI: 0.44–0.66) lower odds of peripheral obesity than in Quartile 1. For central obesity, participants living in Quartile 3 of EVI250m had 1.85 cm (β −1.85, 95% CI: −2.54, −1.15) lower waist circumference, 1.12% (β −1.12, 95% CI: −1.56, −0.67) lower waist-to-height ratio% (WHtR%), and 33% (OR 0.67, 95% CI: 0.57–0.78) lower odds of central obesity than in Quartile 1 of EVI250m. ConclusionsHigher levels of greenness were statistically significant associated with lower obesity risk.