MMP-8 (r = 0.15, p = 0.043), MMP-9 (r = 0.18, p = 0.011) and adiponectin (r = 0.26, p =< 0.001) also correlated weakly with the percentage of emphysema as defined by low attenuation area on chest CT scans; MMP-9 correlated with the radiologists' score of emphysema (r = 0.18, p = 0.010). Here, MMP9 is linked to pulmonary emphysema.