Residential PM2.5 and greenness may modify the effect of physical activity on lung function

Whether environmental factors modify the effect of physical activity on lung function is unknown. We assessed whether individual-level residential NO2, PM2.5 and greenness (mean NDVI in a 500m buffer) levels modify the effect of increased physical activity on higher lung function in the ECRHS cohort (N = 3564). Associations between being active (>2 times and >1 hour per week) at ECHRS II (27-57 years) and FEV1 and FVC at ECRHS II and III (39-67 years), assessed using mixed linear regression models, were stratified by whether participants lived in areas with low/medium ( 75 percentile) NO2, PM2.5 and greenness levels at ECRHS II. The effect of being active (compared to non-active) on FVC was greater in areas with high PM2.5 levels compared to low/medium levels (Figure; p-value for interaction: 0.047). The same was true for greenness for FEV1 (p-value: 0.017) and FVC (p-value: 0.030). Figure: Associations between being active and FEV1 (red circles) and FVC (black stars) stratified by NO2, PM2.5 and greenness, adjusted for sex, age, age 2 , height, weight, smoking status, secondhand smoke exposure, education and occupation. A positive estimate means those active at ECRHS II had higher average lung function at ECRHS II and III. In conclusion, in areas of high PM2.5 or high greenness levels, the effect of physical activity on lung function was greater. Funding: ALEC (EU H2020 Grant #633212)