Chronic obstructive pulmonary disease (COPD) is a heterogeneous and systemic condition characterized by chronic respiratory symptoms (dyspnea, cough, sputum production) due to abnormalities of the airways and/or alveoli that cause persistent, often progressive, airflow obstruction. COPD is a major cause of morbidity because affected individuals experience chronic and progressive respiratory symptoms [1]. In 2019, the global prevalence of COPD among subjects in a 30-to-79 age range, according to the case definition provided by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) [2], was 10.3% (95% CI 8.2–12.8), and it is currently the third leading cause of death worldwide, causing 3.23 million deaths in 2019 [3].
