Association of residential greenness with incident chronic obstructive pulmonary disease: A prospective cohort study in the UK Biobank

Background: Residential greenness has been linked to respiratory mortality, but its long-term effect on incident chronic obstructive pulmonary disease (COPD) has rarely been investigated.Methods: This prospective cohort study was based on over 350 000 participants aged 38-70 of the UK Biobank, followed from 2006 to 2010 baseline to 2021. COPD cases were ascertained through linkages to health administrative datasets. Residential greenness was measured by satellite-derived normalized difference vegetation index (NDVI) within the 500- and 1 000-m buffer. Effects of greenness on COPD incidence were assessed using Cox proportional hazards models. We also explored mediation by physical activity, particular matter <2.5 mu m in aerodynamic diameter (PM2.5) and nitrogen oxides (NOx). Restricted cubic spline models were fit to assess exposure-response relationships.Results: A total of 363 212 individuals (mean [SD] age, 56.2 [8.1] years; 193 181 [53.2 %] women] were included in the analyses. 8 261 COPD cases occurred over 4 287 926 person-years of follow-up. We observed 8% lower COPD risk per IQR increase in NDVI in the 500-m buffer (95% CI: 0.89, 0.95). The association between greenness in the 500-m buffer and COPD were partially mediated by physical activity (1.0%, 95% CI: 0.2%, 1.8%), PM2.5 (21.0%, 95% CI: 3.7%, 38.4%) and NOx (17.0%, 95% CI: 2.8%, 31.2%). Similar results were observed for NDVI within 1 000-m buffer.Conclusions: Long-term exposure to residential greenness was associated with lower risk of COPD incidence among UK adults. Our findings provide a rationale for greening policies as part of respiratory health promotion efforts.