Association of short-term fine particulate matter exposure with pulmonary function in populations at intermediate to high-risk of cardiovascular disease: A panel study in three Chinese cities.

BACKGROUND: Decline in pulmonary function contributes to increasing cardiovascular disease (CVD) risk. Although adverse effects of short-term exposure to fine particulate matter (PM2.5) on pulmonary function have been recognized in healthy people or patients with respiratory disease, these results were not well illustrated among people with elevated CVD risk. MATERIALS AND METHODS: A panel study was conducted in three Chinese cities with three repeated visits among populations at intermediate to high-risk of CVD, defined as treated hypertension patients or those with blood pressure ≥ 130/80 mmHg, who met any of the three conditions including abdominal obesity, dyslipidemia, and diabetes mellitus. Individualized PM2.5 exposure and pulmonary function were measured during each seasonal visit. Linear mixed-effect models were applied to analyze the associations of PM2.5 concentrations with pulmonary function indicators, including forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC), maximal mid-expiratory flow (MMF), and peak expiratory flow (PEF). RESULTS: Short-term PM2.5 exposure was significantly associated with decreased pulmonary function and an increment of 10 µg/m3 in PM2.5 concentrations during lag 12-24 hour was associated with declines of 41.7 ml/s (95% confidence interval [CI]: 7.7-75.7), 0.35% (95% CI: 0.01, 0.69), and 20.9 ml/s (95% CI: 0.5-41.3) for PEF, FEV1/FVC, and MMF, respectively. Results from stratified and sensitivity analyses were generally similar with the overall findings, while the adverse effects of PM2.5 on pulmonary functions were more pronounced in those who were physically inactive. CONCLUSIONS: This study first identified short-term exposure to PM2.5 was associated with impaired pulmonary function and physical activity might attenuate the adverse effects of PM2.5 among populations at intermediate to high-risk of CVD. These findings provide new robust evidence on health effects of air pollution and call for effective prevention measures among people at CVD risk.