Skin measurements
| COPD | Control | p Value | |
| Area of dermis occupied by elastin fibres, % | |||
| Sun-exposed skin | 43.5 (12.1) | 26.3 (6.9) | <0.001 |
| Non-sun-exposed skin | 22.4 (5.2) | 18.1 (4.3) | 0.02 |
| mRNA expression, %† | |||
| SES MMP-2 | +14 (−1 to 30) | 0.06 | |
| SES MMP-9 | +48 (16 to 79) | 0.004 | |
| SES MMP-12 | Insufficient expression for analysis | ||
| SES TIMP-1 | +15 (−1 to 31) | 0.06 | |
| NSES MMP-2 | −3 (−21 to 12) | 0.6 | |
| NSES MMP-9 | +17 (−35 to 74) | 0.5 | |
| NSES MMP-12 | Insufficient expression for analysis | ||
| NSES TIMP-1 | −4 (−22 to 13) | 0.6 | |
| Protein quantification, mg/ml* | |||
| SES proMMP-2 | 22.3 (16.7–24.7) | 20.8 (16.5–33.5) | 0.85 |
| SES MMP-2 activity | 13.6 (10.3–24.8) | 22.7 (13.0–29.4) | 0.25 |
| SES total MMP-2 | 33.3 (22.9–36.5) | 29.9 (23.7–45.8) | 0.93 |
| SES proMMP-9 | 11.7 (7.3–18.1) | 7.7 (4.9–9.4) | 0.02 |
| NSES proMMP-2 | 27.7 (19.5–37.6) | 35.6 (28.6–47.6) | 0.08 |
| NSES MMP-2 activity | 10.1 (6.4–15.2) | 9.9 (8.4–13.3) | 1.0 |
| NSES total MMP-2 | 17.7 (12.9–26.0) | 23.5 (19.6–36.6) | 0.06 |
| NSES proMMP-9 | 9.1 (6.1–11.5) | 10.9 (8.9–12.2) | 0.12 |
mRNA expression calculated as the percentage difference in the COPD group relative to the control data.
Data presented as mean (SD) and analysed using Student t tests, except * median (IQR) analysed using Mann–Whitney U test and † percentage (CIs).
COPD, chronic obstructive pulmonary disease; MMP, matrix metalloproteinase, NSES, non-sun-exposed skin; SES, sun-exposed skin; TIMP, tissue inhibitor of metalloproteinase.