Role of vasoactive intestinal peptide in chronic obstructive pulmonary disease with pulmonary hypertension.

BACKGROUND

The aim of this study was to define the involvement of some biomarkers in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), with particular attention to sub-groups with a PH that is "out of proportion" (OP).

MATERIALS AND

METHODS

Patients with COPD without PH, with PH and marked airways obstruction, and with PH and mild airways obstruction were compared. Assays for human interleukin-6 (IL-6), leukotriene B4 (LTB4), vasoactive intestinal peptide (VIP), and endothelin-1 (ET-1) were performed on the blood samples taken during right heart catheterization (RHC) in a pulmonary artery.

RESULTS

In all, 83 patients were enrolled and divided into three groups: 37 simple COPD (mean pulmonary artery pressure [mPAP] <25 mmHg) and 46 COPD with PH (mPAP ≥25 mmHg). Among the latter, those who had a mPAP ≥35 mmHg and forced expiratory volume in 1 sec [FEV1] ≥50% were classified as OP (7 patients). Patients with PH were older and had a body mass index (BMI) higher than the other groups; moreover, they had lower FEV1 and carbon monoxide diffusion (DLCO) values. A lower level of partial pressure of oxygen in arterial blood (PaO2) was observed in the group of OP patients. The levels of ET-1, IL-6, and LTB4 were similar in each group; VIP was higher in the OP patients than in simple COPD and was related to PAP.

CONCLUSIONS

In the patients with COPD and PH and in particular in the group of OP PH, VIP is significantly increased, probably to correct the imbalance between vasoconstrictor and vasodilatator mediators.