Table 1 Baseline demographic and clinical characteristics

Age(year)

69.43±6.44

67.49±6.17

68.26±7.03

67.22±7.35

0.498

0.685

Smoking index

513.04±559.47

356.52±389.44

380.87±448.49

355.22±446.89

0.603

0.614

BMI(kg/m²)

20.86±4.41

22.09±3.37

21.86±3.03

22.99±2.28

1.662

0.188

FFMI(kg/m²)

16.47±2.20

15.51±2.35

15.76±2.72

16.82±1.38

1.740

0.165

PImax>60cmH₂O

72.73±12.59(n=12)

75.01±17.91(n=9)

75.79±9.79(n=8)

72.55±8.52(n=11)

0.211

0.888

PImax≤60cmH₂O

46.12±11.03(n=11)

44.6±10.87(n=14)

43.83±10.41(n=15)

52.29±8.21(n=12)

1.795

0.161

PEmax (cmH₂O)

63.82±18.46

60.26±19.96

56.10±16.73

62.13±13.56

0.844

0.473

mMRC

1.609±0.839

1.652±0.832

1.913±0.793

1.478±0.790

1.155

0.332

FVC(L)

2.312±0.781

2.229±0.673

2.076±0.813

2.298±0.593

0.517

0.671

FEV₁(L)

1.137±0.462

1.161±0.325

0.967±0.292

1.120±0.339

1.375

0.256

FEV₁%pred (%)

48.217±15.030

46.652±13.506

42.565±12.033

47.248±12.404

0.806

0.494

FEV1/FVC

0.501±0.123

0.534±0.108

0.505±0.172

0.495±0.112

0.554

0.648

6MWD(m)

415.130±52.301

398.957±78.733

382.087±81.637

400.652±78.016

0.776

0.510

CAT

10.478±5.846

10.696±4.106

12.609±4.131

10.348±5.149

1.094

0.356

SGRQ

16.435±7.415

17.348±6.184

18.783±5.018

17.565±7.051

0.511

0.676

HADS

5.870±3.293

5.174±2.125

5.696±2.835

5.000±3.568

0.436

0.727

BODE

2.870±1.576

3.304±1.636

3.826±1.154

2.783±1.930

2.614

0.062