Circulating Plasma Ghrelin and Obestatin Levels Are Low in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Artery Hypertension

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, was firstly identified from rat stomach and cloned in rats and humans. Recently, ghrelin has been shown to participate in cardiovascular and sympathic regulations and play a useful role in some cardiovascular diseases including heart failure, myocardial infarction and pulmonary hypertension. We investigated the fasting plasma ghrelin and obestatin levels and their relationships between them and some other hemodyanmic parameters in chronic obstructive pulmonary disease (COPD) patients with PAH. We found that fasting plasma ghrelin and obestatin levels were significantly lower in PAH group compared with those of the control group (253.8 ± 2.2 pg/ml vs 266.1 ± 2.9 pg/ml; 21.3 ± 0.2 pg/ml vs 22.4 ± 0.3 pg/ml; respectively). In a multiple regression model analysis, only insulin was an independent predictor of fasting ghrelin in COPD patients with PAH (standardized coefficient = 0.555, P = 0.021). We thought that there was imbalance expression of ghrelin and obestatin in COPD patients with PAH and ghrelin and obestatin might play a role in the pathophysiologic progress of COPD patients with PAH.