Table 1 Subject characteristics

Age (years)

61 ± 6

63 ± 5

64 ± 3

64 ± 7

Female: Male

1:4

3:5

4:2

1:5

Cigarette smoking

(pack years)

0 ± 0

36 ± 16

34 ± 12

40 ± 6

Body mass index (kg/m²)

24 ± 5

25 ± 4

29 ± 7

23 ± 3 #

CAT score

2 (0–6)

8 (2–15)

16 (4–23)

24 (20–26)**#

FEV₁ (L)

2.9 ± 0.4

2.9 ± 0.7

1.9 ± 0.3

0.8 ± 0.3**###

FEV₁ (% pred)

100 ± 9

103 ± 11

71 ± 5*

30 ± 11**##

FVC (L)

4.3 ± 0.8

4.4 ± 1.0

3.0 ± 0.7

3.1 ± 1.3

FEV₁/FVC (%)

69 ± 6

67 ± 7

63 ± 8

28 ± 9**##

TLCOc (% pred)

90 ± 14

80 ± 10

67 ± 8*

38 ± 13**##

6-min walk (m)

657 ± 18

631 ± 55

493 ± 66**

364 ± 65**##

VO₂ Peak (ml/kg/min)

28 ± 3

25 ± 3

17 ± 3**

12 ± 4**#

QMVC (Kg)

34 ± 6

41 ± 11

31 ± 8

32 ± 6

QMVC/BMI

1.5 ± 0.1

1.6 ± 0.4

1.1 ± 0.3*

1.4 ± 0.2

SPPB

12

12 (11–12)

11 (10–12)

11 (9–12)