Table 1 Baseline population characteristics

General characteristics

 Gender, male; n (%)

9 (90)

 Age, years; mean (SD)

71.7 (6)

 Former smoker, n (%)

8 (80)

 BMI, kg/m²; mean (SD)

28.5 (5)

 GAP index, median (p25-p75)

3 (2–3)

Treatments, n (%)

 Antifibrotic therapy

9 (90)

 Ambulatory oxygen therapy on exertion

8 (80)

 Ambulatory 24-h oxygen therapy

4 (40)

Comorbidities, n (%)

 Hypertension

4 (40)

 Dyslipidemia

4 (40)

 Diabetes mellitus

3 (30)

 Sleep apnea

2 (20)

 Ischemic heart disease

2 (20)

 Pulmonary emphysema

2 (20)

 Pulmonary hypertension^a

4 (40)

 Charlson comorbidity index; mean (SD)

4.1 (1.2)

Pulmonary function tests, mean (SD)

 FEV₁, % pred

62 (13)

 FVC, % pred

58 (11)

 DL_CO, % pred

31 (13)

6-min walking test, mean (SD)

 Distance, m

436 (131)

 Distance, % pred

90 (20)

 Initial SpO₂, %

91 (4)

 Minimum SpO₂, %

76 (7)

 Mean SpO₂, %

81 (4)

 ΔSpO₂, %^b

− 18 (10)

Peripheral muscle strength, mean (SD)

 Quadriceps strength, kg

41 (14)

 Quadriceps strength, % pred

109 (39)

 Hand-grip, kg

30 (12)

 Hand-grip, % pred

111 (30)