EDN1 and chronic obstructive pulmonary disease: In terms of COPD-PH diagnosis, hs-CRP showed sensitivity of 90.91%, specificity of 85.96%, area-under-the-curve (AUG) of 0.899, and critical value of 38.49 (mg/L); IL-6 showed sensitivity of 87.27%, specificity of 89.47%, AUG of 0.929, and critical value of 98.99 (pg/mL); IL-10 showed sensitivity of 81.82%, specificity of 68.42%, AUG of 0.854, and critical value of 4.740 (pg/mL), and ET-1 showed sensitivity of 87.27%, specificity of 57.89%, AUG of 0.805, and critical value of 39.64 (pg/mL).