Table 1 Baseline characteristics of the study participants

Demographics

Age, years

56.4 ± 13.5

59.0 ± 13.9

53.9 ± 11.6

− 4.5; 9.7

− 1.5; 11.7

− 9.0; 4.0

Sex, male n (%)†

10 (33)

10 (33)

12 (40)

–

–

–

BMI, kg/m²

23.9 ± 3.6

25.4 ± 4.36

25.8 ± 5.67

− 0.53; 3.55

− 3.05; 2.09

− 0.44; 4.42

Breathhold

CP, s

18.30 ± 9.18

12.13 ± 5.96

13.83 ± 7.05

− 10.18; − 2.15

− 5.07; 1.67

− 8.70; − 0.23

MP, s

30.77 ± 12.62

18.70 ± 6.17

24.00 ± 10.88

− 17.24; − 6.89

− 9.90; − 0.70

− 12.86; − 0.68

Spirometry

FEV₁, %predicted

93 ± 15

69 ± 22

80 ± 16

− 34; − 14

− 21; − 1

− 21; − 5

Capnovolumetry

asinh(s2)

1.42 ± 0.25

1.38 ± 0.36

1.44 ± 0.33

− 0.20,0.12

− 0.24,0.12

− 0.13,0.17

asinh(s3)

0.07 ± 0.05

0.19 ± 0.15

0.14 ± 0.12

0.06,0.18

− 0.02,0.12

0.02,0.12

asinh(s3/s2)

0.04 ± 0.03

0.11 ± 0.09

0.07 ± 0.06

0.04,0.11

 > 0.00,0.08

0.01,0.06

Threshold deadspace, mL

92.3 ± 24.3

85.0 ± 28.0

93.7 ± 31.3

− 20.8; 6.3

− 24.0; 6.7

− 13.1; 15.9

Symptoms

Asthma Control Questionnaire (ACQ), score

–

2.03 ± 1.11

1.64 ± 1.13

–

− 0.18; 0.97

–

Nijmegen Questionnaire (NQ), score

3.53 ± 5.07

19.3 ± 10.1

15.6 ± 7.4

11.6; 19.9

− 0.9; 8.3

8.8; 15.4

Medication

β₂-Agonists (salbutamol equivalents), µg/d

–

290.5 ± 193.6

310.5 ± 267.8

–

− 141.1; 101.0

–

ICS (BDP equivalents), µg/d

–

875.8 ± 849.0

740.8 ± 593.0

–

− 244.5; 514.4

–

Inflammation

FeNO, ppb

20.2 ± 11.8

31.7 ± 23.3

35.8 ± 33.1

2.0; 21.2

− 18.9; 10.7

2.7; 28.7