Table 1 Baseline characteristics of COPD patients and smokers without COPD included in the study

Sex (male%)

66

62

N.S.

Age (years)^a

57 ± 8

57 ± 8

N.S.

BMI (Kg/m²)^a

27 ± 5

28 ± 4

N.S.

Smoking habit^c

(pack-yrs)^ac

60 ± 25

44 ± 22

<0.0001

Active smoking (%)

50

64

0.027

T/S ratio^a

0.68 ± 0.25

0.88 ± 0.52

<0.0001

FEV₁ (L)^a

1.66 ± 0.7

2.9 ± 0.7

<0.0001

FEV₁ (% pred)^a

59 ± 21

101 ± 14

<0.0001

FVC (% pred)^a

89 ± 22

108 ± 15

<0.0001

FEV₁ / FVC (%)^a

53 ± 12

76 ± 5

<0.0001

PaO₂ (mmHg)^a

72.3 ± 14.3

78.7 ± 10

<0.001

K_CO (%)

79.6 ± 25.1

97.3 ± 21.3

0.001

IC/TLC (%)

36 ± 9

45 ± 8

<0.001

6MWD (m)^a

523 ± 89

551 ± 76

0.03

mMRC dyspnea^b

1 (0–2)

0 (0–0)

0.006

BODE index^b

1 (0–3)

0 (0–1)

<0.001

Charlson index^b

0 (0–1)

0 (0–0)

N.S.