Table 2 Demographics, MMP-9 and TIMP-1 levels and the MMP-9/TIMP-1 ratio in COPD patients and healthy controls

Age, years, mean ± SD^a

63.4 ± 4.3

61.7 ± 4.3

0.123

Male, n (%)^b

58.2%

46.8%

Female, n (%)

41.8%

53.2%

0.199

Current smokers, n (%)^b

35 (35.7%)

14 (29.8%)

0.489

MMP-9 (ng/ml), med (95% CI)^c

848.7 (728.6–981.5)

58.7 (47.9–76.2)

p ≤ 0.001

TIMP 1 (ng/ml), med (95% CI)^c

234.7 (222.5–246.1)

82.3 (73.0–89.7)

p ≤ 0.001

MMP-9/TIMP-1 ratio, med (95% CI)^c

3.4 (2.9–4.2)

0.40 (0.3–0.5)

p ≤ 0.001