Table 2 Subjects’ clinical characteristics (mean ± SD)

Female/male

0/10

0/10

0/20

–

–

Age (year),

62 ± 4.7

65 ± 5.6

65 ± 5.8

0.870

0.427

Smoking index (pack-years)

0

49.5 ± 18.3^***

39.1 ± 23.5^***

1.488^b

0.233

Body mass index (BMI, kg/m²)

23.9 ± 3.6

21.6 ± 2.9

22.8 ± 2.7

1.245

0.300

FVC (%pred)

94.3 ± 17.6

90.0 ± 13.1

86.25 ± 11.8

1.169

0.322

FEV₁ (%pred)

101.3 ± 12.2

92.0 ± 12.1

72.8 ± 11.9^***##

21.163

< 0.001

FEV₁/FVC

84.3 ± 6.0

77.0 ± 9.8

63.2 ± 6.7^***###

30.323

< 0.001

FRC (%pred)

93.3 ± 21.6

113.1 ± 17.1

128.2 ± 27.0^**

6.878

0.003

TLC (%pred)

113.3 ± 11.4

124.3 ± 12.6

129.0 ± 12.4^**

5.123

0.011

DL_CO (%pred)

115.5 ± 16.5

81.9 ± 11.8^**

73.2 ± 24.6^***

14.715

< 0.001

Pathology, Non-malignant/ Lung cancer

2/8

2/8

1/19

2.414^a

0.264

CAT score, mild /moderate /severe

–

10/0/0

7/12/1^##

12.101^ab

0.001

mMRC classification, 0/1/2

–

6/4/0

9/10/1

0.969^ab

0.800