Table 1.
Characteristics of the participants in the four North European sites of the Burden of Obstructive Lung Disease follow-up study.
| Demographics/Anthropometrics | ||||||
|---|---|---|---|---|---|---|
| All n = 1238 |
Reykjavik n = 371 |
Bergen n = 296 |
Uppsala n = 266 |
Tartu n = 305 |
p-value | |
| Age (years) | 68.1 ± 8.9 | 66.8 ± 8.3 | 69.6 ± 8.8 | 68.0 ± 8.4 | 68.3 ± 9.7 | < 0.001 |
| Women | 46.9 | 45.6 | 46.6 | 42.9 | 52.5 | 0.121 |
| Smoking status | < 0.001 | |||||
| Never | 43.4 | 40.2 | 34.8 | 43.6 | 55.4 | |
| Former | 44.6 | 49.1 | 49.7 | 49.4 | 30.2 | |
| Current | 12.0 | 10.8 | 15.5 | 7.0 | 14.4 | |
| BMI (kg/m2) | < 0.001 | |||||
| < 18.5 | 0.3 | 0.3 | 0.0 | 0.0 | 1.0 | |
| 18.5–24.9 | 27.0 | 19.1 | 38.5 | 33.2 | 20.0 | |
| 25–29.9 | 42.2 | 43.4 | 42.2 | 44.7 | 38.7 | |
| ≥ 30 | 30.5 | 37.2 | 19.3 | 22.1 | 40.3 | |
| Blood inflammatory markers | ||||||
|---|---|---|---|---|---|---|
| n = 1238 | n = 371 | n = 296 | n = 266 | n = 305 | p-value | |
| Total WBC (109/L) | 6.1 ± 2.1 | 5.9 ± 2.3 | 6.1 ± 2.4 | 6.5 ± 2.1 | 6.1 ± 1.6 | 0.014 |
| Neutrophils (109/L) | 3.4 ± 1.2 | 3.1 ± 1.0 | 3.4 ± 1.2 | 3.7 ± 1.3 | 3.5 ± 1.2 | < 0.001 |
| Lymphocytes (109/L) | 1.9 ± 1.5 | 2.0 ± 1.9 | 1.9 ± 1.7 | 1.9 ± 1.3 | 1.8 ± 0.6 | 0.772 |
| NLR | 2.0 ± 1.0 | 1.8 ± 0.8 | 2.0 ± 1.0 | 2.2 ± 1.1 | 2.1 ± 1.0 | < 0.001 |
| Monocytes (109/L) | 0.53 ± 0.16 | 0.51 ± 0.15 | 0.52 ± 0.17 | 0.55 ± 0.18 | 0.52 ± 0.15 | 0.009 |
| Eosinophils (109/L) | 0.18 (0.13) | 0.2 (0.2) | 0.2 (0.2) | 0.13 (0.12) | 0.15 (0.12) | < 0.001 |
| Basophils (109/L) | 0.03 (0.08) | 0.0 (0.10) | 0.0 (0.10) | 0.04 (0.03) | 0.04 (0.04) | < 0.001 |
| Post-bronchodilatory lung function | ||||||
|---|---|---|---|---|---|---|
| n = 1056 | n = 337 | n = 276 | n = 239 | n = 204 | p-value | |
| FEV1 (%pred) | 95.3 ± 16.5 | 92.1 ± 15.8 | 96.0 ± 15.9 | 95.4 ± 16.6 | 99.5 ± 17.1 | < 0.001 |
| FVC (%pred) | 96.0 ± 14.2 | 94.2 ± 13.8 | 96.7 ± 13.8 | 94.0 ± 14.4 | 100.5 ± 14.1 | < 0.001 |
| FEV1/FVC (%pred) | 99.0 ± 9.9 | 97.5 ± 10.6 | 99.0 ± 10.1 | 101.1 ± 8.0 | 98.7 ± 10.2 | < 0.001 |
| CAO | 10.1 | 12.5 | 10.5 | 4.6 | 12.2 | 0.011 |
| Respiratory symptoms | ||||||
|---|---|---|---|---|---|---|
| n = 1229 | n = 371 | n = 296 | n = 257 | n = 305 | p-value | |
| Cough w/o cold | 26.8 | 34.8 | 22.0 | 26.8 | 21.6 | < 0.001 |
| Chronic cough | 9.0 | 13.0 | 6.8 | 7.9 | 7.2 | 0.014 |
| Phlegm w/o cold | 18.2 | 17.8 | 20.9 | 17.5 | 16.7 | 0.558 |
| Chronic phlegm | 9.3 | 11.0 | 10.5 | 8.2 | 6.9 | 0.232 |
| Wheeze | 20.7 | 24.3 | 19.6 | 18.7 | 19.3 | 0.255 |
| mMRC ≥ 2 | 6.0 | 6.9 | 2.3 | 7.9 | 6.7 | 0.051 |
Data are presented as mean ± SD, median (IQR) or %, as appropriate. BMI = body mass index, WBC = white blood cell, NLR = neutrophil-lymphocyte ratio, FEV1 = forced expiratory volume in the 1 st second, FVC = forced vital capacity, CAO = chronic airflow obstruction, defined as FEV1/FVC values below 5th percentile, mMRC = modified Medical Research Council dyspnoea scale.