Table 1. The basic information of the study subjects.

Parameter	Value
N	44
Sex (male/female)	Dec-32
Age (years)	68.2±8.5
BMI (kg/m2)	24.4±4.2
Never/current/ex-smokers	14/19/11
Smoking history (pack-years)*	39.5±17.6
Hospitalization time [days]	14 [12-17]
Exacerbation frequency (times/year)	0.53±0.21
Course of disease (years)	10.3±5.4

BMI, body mass index; *, includes only 30 current/ex-smokers; Values are mean ± standard deviation (SD) or median (range).