Figure 1

Endothelin-1 (expressed as pg/ml) concentration in EBC of the 3 groups: COPD (36), COPD + PAH (12), and healthy subjects (HS) (15). Significance was established at a p value < 0.05. The horizontal lines represent median value. ET-1 in EBC was increased in all COPD patients compared to control group (p < 0.0001). In COPD+PAH group, ET-1 levels were significantly increased compared to both the COPD only and the control group (p < 0.0001).