Dynamic associations between long-term exposure to ambient air pollution and respiratory-cardiovascular diseases: A...

Exposure to ambient air pollution constitutes a significant risk factor for both chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD). However, its impact on the progression of respiratory-cardiovascular disease trajectories, particularly among individuals with COPD, remains unclear. This study aims to assess the associations of long-term air pollution exposure with the progression from a healthy state to the development of COPD, subsequent CVD, and mortality, utilizing a multi-state modeling framework.

We included 318,282 participants from the UK Biobank who were free of COPD and CVD at baseline in this prospective cohort study. Annual average concentrations of particulate matter (PM₂.₅, PM₁₀) and nitrogen oxides (NO₂, NOₓ), derived from participant residential histories and data from the UK's Department for Environment, Food and Rural Affairs (DEFRA), were used to estimate long-term exposure. Multi-state models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for each 1 µg/m³ increase in air pollutant concentration in relation to disease transitions along the respiratory-cardiovascular trajectory.

During a median follow-up period of 13.5 years, 6901 participants developed COPD; 2207 of whom subsequently developed CVD, and 15,921 participants died. All pollutants were significantly associated with adverse transitions in the respiratory-cardiovascular disease trajectory, Adjusted HRs (95 % CIs) per 1 µg/m³ increase in pollutant exposure for the transition from COPD to CVD were: NO₂, 1.013(1.006,1.020); NO_X, 1.005(1.001,1.009); PM_2.5, 1.051(1.035, 1.068); and PM₁₀, 1.068(1.045,1.093). Subgroup analyses revealed greater risks among specific populations, particularly among female COPD patients (HR for PM₂.₅=1.106) and individuals aged ≥ 55 years (HR for PM₂.₅=1.132).

Chronic exposure to ambient air pollution, particularly PM₂.₅ and PM₁₀, is linked to an elevated risk of progression from COPD to CVD, thereby augmenting the overall burden of respiratory-cardiovascular diseases. These findings highlight the urgent need for effective air quality interventions to reduce pollution-related health impacts.