Increased Risk of Severity in COPD with Eosinophilic Inflammation due to Air Pollution Exposure

<bold>Background:</bold> Air pollution exacerbates chronic obstructive pulmonary disease (COPD) symptoms, particularly in cases with eosinophilic inflammation. This study probes the correlation between particulate deposition, lung function decline, and emphysema severity in such COPD cases. <bold>Methods:</bold> We analyzed 111 COPD patients with emphysema. Emphysema severity was measured via high-resolution computed tomography (HRCT), using voxel counts. Air pollution exposure was quantified with a hybrid kriging and land use regression model, while lung particle deposition was estimated through the Multiple-Path Particle Dosimetry Model (MPPD). Regression models were used to examine the associations of air pollution and particle deposition with emphysema severity in eosinophilic COPD. <bold>Results:</bold> A 1 μg/m³ increase in PM₁₀ over 1, 3, and 5 years corresponded to declines in FEV₁ (0.73%, 0.83%, 0.82%) and FEV1/FVC (0.41%, 0.44%, 0.47%). A similar PM₁₀ increase showed 0.84% and 0.87% increases in low attenuation areas (LAA) in the upper lobe over 1 and 3 years, respectively. In the lower lobe, the increases were 1.47%, 1.55%, and 1.50%. In COPD with eosinophilic inflammation, these PM₁₀ increases were significantly associated with elevated upper and lower lobe impacts. <bold>Conclusions:</bold> The study confirms a relationship between particulate air pollution exposure/deposition and the aggravation of lung function and emphysema in eosinophilic COPD patients. These patients are more vulnerable to particulate inhalation, with greater effects in the upper lung lobes.