Clinical characteristics of participants
| Parameters | Healthy controls (n=49) | COPD patients (n=84) | P-value |
| Age (years) | 59.3±15.6 | 61.5±8.9 | 0.084 |
| Sex (M:F) | 30/19 | 55/29 | 0.327 |
| BMI (kg/m2)* | 25.7±2.5 | 21.3±2.8 | <0.001 |
| Non-smoker,ex-smoker and current smoker | 3/15/31 | 5/32/47 | 0.527 |
| Pack per year* | 19.2±10.5 | 33.7±14.6 | <0.001 |
| Number inhaled (ICS/LABA/LAMA) | NA | 75/78/81 | NA |
| CAT | NA | 22.8±6.5 | NA |
| Pulmonary function | |||
| FEV1 %predicted* | 97.5±23.1 | 47.1±22.5 | <0.001 |
| FEV1/FVC ratio* | 87.3±4.8 | 51.4±10.6 | <0.001 |
Parametric parameters were presented as mean±SD. Differences between healthy controls and COPD patients (*p<0.001). P<0.05 was considered significant. Body mass index (BMI)= weight (kg)/height (m2).
CAT, Chronic Obstructive Pulmonary Disease Assessment Test; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; ICS, inhaled corticosteroids; LABA, long-acting β-adrenoceptor agonists; LAMA, a long-acting muscarinic antagonist; NA, not applicable.