Clinical Profile and Predictors of Asthma-Chronic Obstructive Pulmonary Disease Overlap in a Tertiary Care Population in North India

Background: Asthma and chronic obstructive pulmonary disease (COPD) are common chronic airway disorders with distinct pathophysiology. A subset of patients exhibits overlapping clinical, functional, and inflammatory features, termed asthma-COPD overlap (ACO), which is associated with increased disease burden and management challenges. Data on the prevalence and characteristics of ACO using standardized criteria in the Indian population remain limited. The present study was conducted to determine the prevalence of ACO and to compare its demographic, inflammatory, and functional characteristics with asthma and COPD, and identify factors associated with ACO. Methods: This cross-sectional study included 200 clinically stable adults with physician-diagnosed asthma or COPD at a tertiary care center in North India. Patients were classified as asthma, ACO, or COPD using the combined Global Initiative for Asthma (GINA) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) clinical and spirometric criteria. Demographic data, smoking exposure, body mass index (BMI), absolute eosinophil count (AEC), spirometry, resting oxygen saturation (SpO2), and six-minute walk distance (6MWD) were recorded. Groups were compared, and multivariate logistic regression was used to identify factors independently associated with ACO. Results: Fifty-one patients (25.5%) met the ACO criteria. The ACO group showed intermediate age, male predominance, and greater smoking exposure. AEC was significantly higher in ACO than in COPD. Post-bronchodilator forced expiratory volume in one second (FEV₁%), SpO2, and 6MWD were lower than in asthma but higher than in COPD. Increasing age, smoking exposure, and higher blood eosinophil count independently predicted ACO. Conclusion: ACO constituted a considerable proportion of patients among those diagnosed with COPD or asthma. Smoking exposure, persistent eosinophilic inflammation, and functional impairment were intermediate between asthma and COPD.