Abstract: Objective  To investigate the levels of plasma Creactive protein(CRP)，brain  natriuretic peptide (BNP)， endothelialin1(ET1) and pulmonary hypertension(PH) in the patients with chronic obstructive pulmonary disease(COPD) in the plateau region. Methods  A total of 118 patients with COPD were included. Pulmonary artery pressure was measured by Doppler echocardiogram. CRP， BNP and ET1  were tested by ELISA. All the patients were divided into three groups: COPD nonPH(COPDnPH group)，COPD with mild PH(COPDmPH group)， COPD with serious PH(COPDsPH) group serious.Results  As pulmonary artery pressure increased， PO2 decreased， there were significantly differences among three groups (P<0.05). Hb and HCT in COPDsPH group were significantly higher than those of COPDmPH (F=10.672，P<0.05)  and COPDNPH group (F=6.383，P<0.05). There were also significant differences  in the levels of CRP， BNP， and ET1  among three groups(P<0.01). Pulmonary artery systolic pressure was positively associated with CRP (r=0.354，P=0.000)， BNP (r=0.427，P=0.000)， and ET1 (r=0.453，P=0.000).Conclusion  The patients with COPD in the plateau region have worse hypoxemia， greater abnormal Hb and HCT， and higher condensation state of blood， which promotes pulmonary arterial  pressure. As the pulmonary artery pressure increases， the plasma CRP increases， suggesting systemic inflammation may be involved in the PH induced by COPD.

Key words: pulmonary disease, chronic obstructive, altitude, hypertension, pulmonary;Creactive protein, vascular endothelial growth, factors;natriuretic peptide, brain