Airway Response to Dual Bronchodilation and Its Association with Inflammatory Markers in Treatment-Naïve Chronic Obstructive Pulmonary Disease: A Quantitative Computed Tomography Study.

Background/Objectives: Quantitative computed tomography (CT) can be used to characterize airway responses to therapies for chronic obstructive pulmonary disease (COPD), but prospective real-world data in treatment-naïve patients remain limited, and the role of inflammatory markers as potential predictors of structural airway response is poorly understood. Methods: We conducted a prospective real-world study in treatment-naïve patients with moderate-to-severe COPD (n = 47). Lung function and chest CT were assessed at baseline and after 12 weeks of tiotropium/olodaterol (n = 34). Blood eosinophil count and high-sensitivity C-reactive protein (hs-CRP) were measured at baseline. Results: Lung function improved after 12 weeks (p < 0.05). Airway lumen area normalized to body surface area (Ai/BSA) increased from 10.2 ± 2.6 to 12.2 ± 2.7 mm2/m2, whereas relative wall area (WA%) decreased from 58.3 (56.6-61.5) to 55.9 (54.4-57.9)% (both p < 0.001). Improvement in Ai/BSA did not differ between upper and lower lobes (p > 0.05). Higher baseline hs-CRP was associated with a smaller Ai/BSA increase (r = -0.454, p = 0.01). No statistically significant associations were detected between ΔAi/BSA and the evaluated baseline variables, including blood eosinophil count, Ai/BSA, age, smoking history and lung function measurements (all p > 0.05), or between blood eosinophil count and baseline Ai/BSA or WA% (both p > 0.05). Conclusions: Initial dual bronchodilator therapy improved lung function and CT-derived airway measurements. In this cohort, no statistically significant association was detected between blood eosinophil count and airway response, whereas higher hs-CRP was associated with a smaller Ai/BSA increase.