Table 1 Inclusion and exclusion criteria for the study
Inclusion criteria | Exclusion criteria |
|---|---|
• Age ≥ 40 years | 1) Had a history of systemic corticosteroid therapy (prednisone > 0.5 mg/kg or equivalent doses) within 1 month 2) Had a history of diseases that affect immune cells, such as connective tissue diseases, immunological diseases, haematological diseases, liver and renal failure 3) Had a history of asthma, allergic disease, or other clinically significant lung diseases 4) Had a history of heart failure, arrhythmia, mental disorders, or any malignancy |
• SCOPD is defined as respiratory symptoms were stable or mild, and the condition was stable for 3 months | |
• AECOPD is defined as an acute worsening of respiratory symptoms that results in additional therapy • HS is defined as a smoking history of ≥ 20 pack-years and normal lung function | |
• HC is defined as a nonsmoker with normal pulmonary function |