Table 1.

Basic Clinical Information of Participants

Parameters	NC (n = 31)	COPD (n = 21)
Gender (male/female)	31/0	21/0
Age (years)	61.2±6.3	64.5±7.1
Smoking history (pack-years)	34.2±5.2	42.5±6.8*
BMI (kg/m2)	27.8±5.6	29.5 ±6.8
FEV1/FVC%	81.2 ±9.6	65.2±7.3*
FEV1 (% predicted)	98.3 ±4.8	61.3±2.9*

Note: *P < 0.05.

Abbreviations: COPD, chronic obstructive pulmonary disease; BMI, body mass index; FVC, forced vital capacity; FEV₁, forced expiratory volume in one second.