Table 1.

Demographic characteristics of the tested population.

Characteristic	Chronic Obstructive Pulmonary Disease (COPD) Patients	Healthy Controls
Sex
Male	487 (69.2)	1116 (87.3)
Female	217 (30.8)	163 (12.7)
Age, year, median (SD, minimum and maximum)	61 (8.25; 33–85)	38 (12; 16–66)
Smoking History
Non-smoker	56 (8.1)	954 (74.4)
Former	424 (61.5)	3 (0.2)
Active	209 (30.3)	325 (25.3)
Missing data	15 (2.1)	1 (0.1)

Data are presented as number (%).