Table 2 Demographic characteristics of study population

   Age (years)

67.8 ± 9.5

   Sex (Male)

190 (68.6)

   Race (Caucasian)

274 (98.9)

   BMI (kg/m²)

26.3 (23.3–29.4)

Smoking status

   Current smokers, (n) %

74 (26.7)

   Median Pack-years, median, IQR

50 (35–80)

Comorbidities

   Congestive heart disease, %

17.5

   Diabetes mellitus, %

12.9

   Liver disease, %

2.9

   Malignant solid tumour, %

4.0

   Arterial hypertension, %

56.4

   Pulmonary arterial hypertension, %

8.0

History of exacerbations in COPD patients in previous years

   Median duration of COPD (months), median IQR

84 (44.5–130)

   Duration of physician-diagnosed COPD (months), median, IQR

60 (29–120)

   Required unscheduled urgent physician visit, median, IQR

1 (0–2)

   Required hospitalization, median, IQR

0 (0–1)

   Antibiotics use, median, IQR

1 (0–1)

Current medication for COPD

   SABA + SAMA, %

20.6

   LABA + ICS, %

73.5

Single drug inhaler

   SABA, %

31.4

   LABA, %

12.27

   SAMA, %

6.2

   LAMA, %

71.7

   ICS, %

11.7

Lung function tests

   FEV1,L post-BD, mean ± S.D.

1.4 ± 0.6

   FEV1 % predicted post-BD, mean ± S.D.

48.2 ± 17.5

   FVC,L post-BD, mean ± S.D.

2.9 ± 3.8

   FVC % predicted post-BD, mean ± S.D.

77.9 ± 23.2

   FEV1/FVC post-BD, mean ± S.D.

48.0 ± 13.6

GOLD Stages

   GOLD II, (n) %

129 (47.3)

   GOLD III, (n) %

104 (38.1)

   GOLD IV, (n) %

40 (14.6)

SGRQ - Quality of life

   Symptoms score, median IQR

46.3 (29.3–65.8)

   Activity score, median IQR

59.4 (42.4–79.2)

   Impact score, median IQR

30.0 (18.3–46.5)

   Total score, median IQR

41.8 (29.5–57.8)

SF-36 Health Survey

   Physical Function, median IQR

50.0 (25.0–70.0)

   Role Function, median IQR

50.0 (0.0–100.0)

   Role Emotional, median IQR

100.0 (8.3–100.0)

   Social Function, median IQR

75.0 (50.0–100.0)

   Mental Health, median IQR

65.0 (55.0–80.0)

   Body Pain, median IQR

74.0 (51.0–100.0)

   Vitality, median IQR

50.0 (37.5–62.5)

   General Health, median IQR

45.0 (28.3–65.0)

Exercise performance

   6MWD, m, mean ± S.D.

375.5 ± 102.6

   Peripheral Oxygen saturation at rest, mean ± S.D.

94.5 ± 2.7

   Lowest oxygen saturation during test, mean ± S.D.

89.6 ± 6.0

   Heart rate at rest (beats/min), mean ± S.D.

80.8 ± 14.7

   Highest heart rate during test (beats/min), mean ± S.D.

105.9 ± 19.49

   6 min’ walk BORG score, median IQR

4 (3–6)

   BODE index, median IQR

3 (1–4)

Serum MBL level

   Serum MBL concentration, ng/ml, median, IQR

612 (365.5–933.0)

   Low serum MBL level (<75th quartile; <934 ng/ml), (n) %

208 (75.1)

   High serum MBL level (≥75th percentile; ≥934 ng/ml), (n) %

69 (24.9)