TABLE 1.
Baseline characteristics1
| Placebo group (n = 81) | Vitamin D group (n = 74) | |
|---|---|---|
| Age, y | 67 ± 9 | 65 ± 9 |
| Sex, male | 55 (68) | 46 (62) |
| BMI, kg/m2 | 27.4 ± 5.4 | 28.1 ± 5.1 |
| Smoking | ||
| Current smoker | 23 (28) | 25 (34) |
| Ex-smoker | 58 (72) | 49 (66) |
| Pack-years | 41 [21–55] | 40 [26–55] |
| Ethnic origin, European descent | 73 (90) | 68 (92) |
| GOLD-stage | ||
| I | 6.2 | 5.3 |
| II | 42.0 | 44.0 |
| III | 37.0 | 41.3 |
| IV | 14.8 | 9.3 |
| Spirometry | ||
| FEV1, L | 1.43 ± 0.56 | 1.43 ± 0.54 |
| FEV1, %predicted | 50.3 ± 18.4 | 50.0 ± 16.0 |
| FVC, L | 3.31 ± 0.93 | 3.24 ± 0.93 |
| FVC, %predicted | 89.3 ± 18.1 | 88.9 ± 19.8 |
| FEV1:FVC ratio, % | 43 ± 14 | 45 ± 12 |
| Maximal respiratory mouth pressures | ||
| Maximal inspiratory mouth pressure, kPa | 7.1 [5.1–8.8] | 6.3 [5.3–8.2] |
| Maximal expiratory mouth pressure, kPa | 10.2 [7.0–12.8] | 9.6 [7.4–12.2] |
| Serum 25(OH)D concentration, nmol/L | 40 ± 17 | 38 ± 15 |
| Serum 25(OH)D concentration ≤25 nmol/L | 16 (20.5) | 15 (21.4) |
| Inflammatory markers | ||
| CRP, µg/mL | 5.1 [2.3–9.9] | 5.3 [2.7–10.1] |
| IL-6, pg/mL | 5.3 [4.1–9.4] | 5.8 [3.9–8.6] |
| LL-37, ng/mL | 16.8 [12.3–22.4] | 17.9 [13.0–24.0] |
| Physical function | ||
| 6-min walking test, m | 383 ± 122 | 413 ± 117 |
| Handgrip strength test, kg | 35.3 ± 11.3 | 34.6 ± 10.8 |
| Use of vitamin D supplementation | 10 (12) | 6 (8) |
1Values are n (%), percentages, mean ± SD, or median [IQR]. CRP, C-reactive protein; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; 25(OH)D, 25-hydroxyvitamin D.