Table 2. Respiratory symptoms and pulmonary function tests according to chronic obstructive pulmonary disease groups.
| Variable | Non-smoker group | Tobacco smoker group | P value |
|---|---|---|---|
| Respiratory symptoms | |||
| Cough | 11 (69.0%) | 8 (53.3%) | 1.00 |
| Sputum | 6 (37.5%) | 6 (40.0%) | 1.00 |
| Morning throat | 7 (44.0%) | 7 (46.7%) | 1.00 |
| Wheezing | 6 (37.5%) | 5 (33.3%) | 1.00 |
| Dyspnea | 13 (81.2%) | 5 (33.3%) | 0.01 |
| Post-bronchodilator spirometry | |||
| FVC, %predicted | 75.7±18.1 | 83.0±14.1 | 0.20 |
| FEV1, %predicted | 59.8±22.4 | 59.5±16.7 | 0.90 |
| FEV1/FVC | 0.53±0.1 | 0.52±0.1 | 0.70 |
| Lung volumes | |||
| TLC, %predicted | 107.3±22.7 | 112.6±14.0 | 0.50 |
| RV, %predicted | 156.9±45.5 | 170.7±38.1 | 0.40 |
| DLCO | |||
| DSB (mL/min/mmHg) | 11.8±5.0 | 13.6±7.4 | 0.40 |
| DSB, %predicted | 62.6±25.5 | 63.3±27.9 | 0.90 |
| Arterial blood gases | |||
| PaO2 (mmHg) | 66.1±8.5 | 74.8±7.9 | 0.01 |
| Age-adjusted PaO2 (mmHg) | 74.9±5.0 | 79.5±5.4 | 0.02 |
| PaCO2 (mmHg) | 42.6±7.7 | 40.7±5.1 | 0.40 |
| pH | 7.4 | 7.4 | 1.00 |
| SaO2% | 92.5±4.1 | 95.4±2.0 | 0.02 |
Data are reported as means±SD or number and percentage. Statistical analysis was done with Fisher's exact test or Wilcoxon test. FVC: forced vital capacity; FEV1: forced expiratory volume in one second; TLC: total lung capacity; RV: residual volume; DLCO: diffusing capacity of the lung for carbon monoxide; DSB: carbon monoxide diffusion capacity; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension; SaO2%: arterial oxygen saturation.