Table 4. Clinical characteristics of male pneumothorax patients with MMP-2 and MMP-9 expression.
| Variables | Item | Patient No. (%) | MMP-2 | MMP-9 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Low | High | P valuea | Low | High | P valuea | ||||||||||
| No. | % | No. | % | No. | % | No. | % | ||||||||
| Age (years) | ≤20 | 48 (60.8) | 14 | 29.2 | 34 | 70.8 | 0.556 | 21 | 43.8 | 27 | 56.2 | 0.902 | |||
| >20 | 31 (39.2) | 11 | 35.5 | 20 | 64.5 | – | 14 | 45.2 | 17 | 54.8 | – | ||||
| BMI (kg/m2) | <18 | 31 (39.2) | 9 | 29.0 | 22 | 71.0 | 0.688 | 13 | 41.9 | 18 | 58.1 | 0.733 | |||
| ≥18 | 48 (60.8) | 16 | 33.3 | 32 | 66.7 | – | 22 | 45.8 | 26 | 54.2 | – | ||||
| Recurrence | No | 37 (46.8) | 20 | 54.1 | 17 | 45.9 | <0.001 | 24 | 64.9 | 13 | 35.1 | 0.001 | |||
| Yes | 42 (53.2) | 5 | 11.9 | 37 | 88.1 | – | 11 | 26.2 | 31 | 73.8 | – | ||||
| Smoking status | No | 64 (81.0) | 24 | 37.5 | 40 | 62.5 | 0.029 | 32 | 50.0 | 32 | 50.0 | 0.045 | |||
| Yes | 15 (19.0) | 1 | 6.7 | 14 | 93.3 | – | 3 | 20.0 | 12 | 80.0 | – | ||||
| Side involved | Unilateral | 55 (69.6) | 16 | 29.1 | 39 | 70.9 | 0.460 | 26 | 47.3 | 29 | 52.7 | 0.421 | |||
| Bilateral | 24 (30.4) | 9 | 37.5 | 15 | 62.5 | – | 9 | 37.5 | 15 | 62.5 | – | ||||
a, the P value was calculated by the chi-square test. MMP-2, matrix metalloproteinase-2; MMP-9, matrix metalloproteinase-9; BMI, body mass index.