Table 1 Characteristics of proteomics cohorts in discovery stage and in validation stage

N

40

40

29

31

Male, %

100

100

1.0

100

100

1.0

Smoking, %

100

100

1.0

100

100

1.0

Packyears ≥ 30, %

100

100

1.0

100

100

1.0

Age (years), mean (SD)

64.6 (11.7)

63.7 (5.3)

0.656

Height (cm), mean (SD)

165.0 (5.2)

166.0 (5.9)

0.824

164 (4.9)

169 (5.9)

< 0.001

Weight (kg), mean (SD)

63.1 (12.5)

65.7 (8.2)

0.266

60.60 (9.3)

69.10 (9.4)

0.001

BMI (kg/m²), mean (SD)

23.8 (2.9)

23.1 (4.6)

22.40 (3.2)

23.90 (2.5)

0.054

Fan in kitchen, %

93.2

92.7

0.475

92.3

93.6

1.000

Good room ventilation, %

38.6

63.4

0.022

62.1

51.6

0.414

Often preserved food, %

18.8

7.1

0.106

10.3

3.2

0.346

Often cook, %

25.0

29.3

0.658

17.2

35.5

0.110

Comorbidity, %

 CRD

29.8

12.2

0.045

34.6

3.2

0.002

 Hypertension

42.6

31.7

0.294

34.6

22.6

0.314

 Diabetes

12.8

7.5

0.498

0

10

–

 Heart diseases

40.4

12.5

0.004

19.2

6.7

0.231

 Stroke

4.3

0

–

3.8

0

–

Family history, %

 Cancer

6.3

9.5

0.563

23.1

22.6

0.965

 RD without COPD

19.1

15.8

0.759

7.1

3.2

–

 Severe COPD, %

100

0

–

100

0

–

Pulmonary function, mean (SD)

 pre_FVC_%Pred

74.9 (28.1)

98.0 (15.0)

< 0.001

78.5 (16.3)

94.3 (10.4)

< 0.001

 pre_FEV1_%Pred

59.7 (32.1)

88.4 (26.1)

< 0.001

47.1 (14.3)

94.5 (9.6)

< 0.001

 pre_FEV1/FVC_%Pred

62.7 (15.9)

71.3 (15.5)

0.036

57.4 (15.8)

96.8 (9.7)

< 0.001

 post_FVC_%Pred

74.6 (24.6)

99.8 (12.5)

< 0.001

88.3 (14.6)

104 (13.0)

0.061

 post_FEV1_%Pred

57.1 (28.6)

90.8 (25.4)

< 0.001

53.8 (15.8)

101 (10.4)

< 0.001

 post_FEV1/FVC_%Pred

60.7 (15.2)

70.9 (15.4)

0.021

57.7 (15.4)

76.9 (6.3)

0.025