Assessment of prevalence and characteristics of asthma-COPD overlap among patients with chronic airflow obstruction

Abstract

Given the paucity of research on asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) and the high prevalence of co-morbidities and healthcare utilization associated with it, the current study looked at the prevalence of ACO and its clinico-radiological phenotype in patients with chronic airflow obstruction. The study was conducted at a tertiary care hospital in North India. Patients over 40 with COPD or asthma were screened for inclusion in the ACO, asthma, and COPD groups. The ACO and COPD groups were further investigated. The clinical characteristics, lung functions, health-related quality of life, and radiological features of both groups were investigated and compared. ACO was discovered in 16.3% of patients with chronic airflow obstruction (asthma and COPD). The most commonly observed symptoms at presentation in the evaluated ACO patients (n=77) were shortness of breath, wheezing, cough, and expectoration (mean age at presentation: 57.9; mean duration of illness: 8.62 years). Exacerbation rates in ACO patients were significantly higher than in COPD patients (p<0.001). The ACO group had a significantly greater mean change in FEV1 post-bronchodilator in millilitres (ml) and percentage (379.61 ml and 37.72%) than the COPD group (p<0.001). The proportion of patients with emphysema was lower in the ACO group than in the COPD group (p<0.001). The ACO and COPD groups did not differ significantly in major airway wall thickness (p=0.3), but the COPD group had a significantly higher proportion of patients with vascular attenuation and distortion (p<0.001). Patients with COPD had a higher degree of hyperinflation, according to high resolution computed tomography (HRCT) indices. This study found that patients with ACO have a distinct phenotype in terms of clinical presentation and HRCT features. More research on the radiological features of ACO is required to identify the anatomical abnormalities involved in the disease's pathogenesis and to validate the radiological features of ACO.