Long-term exposure to ambient air pollution and incident cardiovascular disease in adults with cardiovascular–kidney–metabolic stages 0–3: a nationwide prospective cohort study in China
摘要
Cardiovascular–Kidney–Metabolic (CKM) stages 0–3 represent a key window for cardiovascular disease (CVD) prevention, yet the effects of long-term ambient air pollution in this population remain unclear. In this longitudinal analysis of a nationwide prospective cohort, we analyzed 6,321 adults without baseline CVD from the China Health and Retirement Longitudinal Study (CHARLS). Long-term exposure to PM2.5, NO2, and warm-season O3 was estimated using the China High Air Pollutants satellite-based dataset, which provides pollutant surfaces at 1-km resolution (10-km for NO₂). Incident CVD through 2018 was physician-diagnosed. Cox models were used to evaluate baseline and time-varying associations, and non-linear and joint effects were examined using spline and multipollutant approaches. During a median follow-up of 6.9 years, 896 participants developed CVD. Each 10 µg/m³ increase in baseline PM2.5 or NO2 was associated with a 20% higher CVD risk (PM2.5: HR 1.20, 95% CI 1.13–1.28; NO2: HR 1.20, 1.07–1.35). Time-varying models confirmed these findings and additionally identified a significant association with O3 (HR = 1.20, 95% CI: 1.11–1.30). Restricted cubic spline analyses indicated non-linear exposure–response relationships, with thresholds of 39.64 µg/m3 for PM2.5 and 39.86 µg/m3 for NO2. Multipollutant models showed a positive mixture effect dominated by PM2.5, and stronger associations were observed in participants from eastern China (P interaction < 0.01). Long-term exposure to PM2.5, NO2, and O3 increases CVD risk in adults with CKM stages 0–3, with PM2.5 as the leading driver. These findings highlight the need to incorporate air pollution into CKM-based cardiovascular prevention strategies.