Abstract: Objective To investigate the serum level and association of vasoactive intestinal peptide (VIP) with hypercoagulability, hypoxemia and vascular endothelial function in the elderly patients with chronic obstructive pulmonary disease (COPD) complicated with pulmonary hypertension (PH). Methods The clinical data of age, gender, forced expiratory volume in one second/percentage of forced vital capacity (FEV1/FVC), fibrinogen (FIB), D-dimer (D-D) and arterial partial perssure of oxygen (PaO₂) were collected from 226 elderly patients with COPD. According to the pulmonary artery systolic pressure (PASP) measured by cardiac color ultrasound, the patients were divided into COPD with PH group (PASP≥40 mmHg, n=76) and COPD group (PASP<40 mmHg, n=150). The levels of serum endothelin-1 (ET-1) and VIP were detected by enzyme-linked immunosorbent assay (ELISA), and the level of serum nitric oxide (NO) was measured by colorimetry. Results There were no significant differences in age, gender, smoking history, the levels of body mass index (BMI), blood glucose, blood pressure and blood lipid between the two groups (P>0.05). FEV1/FVC in COPD with PH group was lower than that in COPD group (P<0.05). After adjusting FEV1/FVC by covariance analysis, the levels of VIP, NO and PaO₂ in COPD with PH group were lower than those in COPD group, and the levels of FIB and D-D were higher than those in COPD group (P<0.05 or P<0.01). Among the patients with PH, VIP was positively correlated with PaO₂(r=0.713, P<0.001), and negatively correlated with D-D (r=-0.670, P<0.001). Conclusions The level of VIP in the elderly patients with COPD-PH is closely related to hypercoagulability, hypoxemia and vascular endothelial function.

Key words: chronic obstructive pulmonary disease, pulmonary hypertension, vasoactive intestinal peptide, hypercoagulable state, hypoxemia, vascular endothelial function