Table 1.
Baseline characteristics of the study population
| Overall population (n=275) | Males (n=226) | Females (n=49) | P-value | |
|---|---|---|---|---|
| Age, years | 70.9±8.4 | 70.9±8.1 | 70.8±9.4 | 0.937 |
| BMI | 26.8±4.6 | 27.1±4.6 | 25.1±4.3 | 0.006 |
| Smoking status | ||||
| Active smoker | 65 (23.6%) | 47 (20.8%) | 18 (36.7%) | |
| Ex-smoker | 184 (66.9%) | 166 (73.4%) | 18 (36.7%) | |
| Ever smoker | 26 (9.5%) | 13 (5.7%) | 13 (26.6%) | |
| FEV1 (L) | 1.5±0.5 | 1.5±0.5 | 1.2±0.5 | 0.001 |
| FEV1 % pred | 55.9±18.8 | 56.1±19.1 | 55.3±17.9 | 0.785 |
| FEV1/FVC (%) | 55.9±10.3 | 55.6±10.5 | 57.2±9.2 | 0.675 |
| FEV1/VC | 51.1±10.6 | 50.7±10.8 | 52.8±9.5 | 0.206 |
| RV% pred | 156.9±46.2 | 156.5±47.4 | 160.4±37.0 | 0.596 |
| TLCO/VA% pred | 70.9±26.2 | 70.1±26.6 | 75.9±24.1 | 0.157 |
| FEV1 reversibility | 6.7±7.9 | 7.1±7.9 | 4.7±7.4 | 0.636 |
| 6′ walking test (m) | 233.3±92.7 | 237.0±92.8 | 216.1±91.7 | 0.149 |
| MRC score | 2.3±1.2 | 2.3±1.2 | 2.4±1.1 | 0.599 |
| BODE index | 4.4±2.6 | 4.3±2.6 | 4.8±2.7 | 0.224 |
| Charlson comorbidity index | 3.3±1.8 | 3.3±1.8 | 3.2±2.0 | 0.730 |
Notes: Means ± SD calculated for each variable at the first visit in the whole sample, in males and females. Statistical comparison is presented by sex (Welch’s t-test).
Abbreviations: 6′ walking test, 6-minutes walking test; BMI, body mass index; FEV1, forced expiratory volume in 1 second; FEV1 reversibility, changes of basal FEV1 value 30 minutes after salbutamol 400 μg; FVC, forced vital capacity; VC, vital capacity; RV, residual volume; TLCO/VA, lung transfer of CO/alveolar volume; MRC score, Medical Research Council dyspnea scale; BODE index, composite index of Body mass index, airflow Obstruction, Dyspnea, and Exercise; pred, predicted; SD, standard deviation.