The Prevalence of Asthma-COPD Overlap Syndrome in Patients with Obstructive Airway Disease in Kerman, Iran

Background: The coexistence of asthma and chronic obstructive pulmonary disease (COPD) is recognized as asthma–COPD overlap syndrome (ACOS). This study aimed to investigate the prevalence of ACOS and the characteristics of the affected patients in terms of chronic pulmonary airway diseases in the southeastern Iran, Kerman.Methods: This cross-sectional study was conducted in Kerman province, Iran, from March 2017 to March 2018. 295 patients with a history of chronic pulmonary airway diseases including asthma and COPD were enrolled through convenience sampling. Spirometry was performed and forced expiratory volume (FEV1), forced vital capacity (FVC), and FEV1/FVC were calculated. The physician made the final diagnosis according to GOLD/GINA criteria. Chi-square, Fisher’s exact test, t-test, and Mann–Whitney U test were used to compare variables through SPSS version 23.Results: The ACOS prevalence was 36.9% (95% CI: 31.5- 42.7). Asthma patients were younger than ACOS patients (P = 0.001) and they had higher levels of FEV1 (P = 0.02), FEF (P ≤ 0.001), and FEV1/FVC (P ≤ 0.001) before receiving bronchodilator in comparison to ACOS patients. However, COPD patients were older than the ACOS patients (P ≤ 0.001). The lung function in ACOS patients before and after receiving bronchodilators was higher for FEV1 and FVC in COPD patients.Conclusion: The prevalence of ACOS was considerable. The present study showed that gender, age, and BMI could be associated with ACOS. The risk factors underlying ACOS and their impact on the patient’s life quality and treatment costs can be investigated by future studies.