Plasma Ghrelin Levels to Predict Severity of Pulmonary Arterial Hypertension Ghrelin in Relation to Pulmonary Hypertension

Background: Pulmonary arterial hypertension (PAH) causes right ventricular (RV) remodeling and dysfunction, which results in clinical deterioration and mortality. Ghrelin which is proposed as a possible biomarker for PAH, is a peptide mostly secreted from gaster, and has various effects on the cardiovascular system. We aimed to determine ghrelin plasma levels in PAH patients and its correlation with RV function and N-terminal pro b-type natriuretic (NT-proBNP) levels. Methods: Eighteen patients (37 +/- 15y,17f) with different etiologies and a matched control group of 20 volunteers were included. Plasma ghrelin levels were studied. RV dimensions, tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), global (G) longitudinal strain (LS) as well as left ventricular (LV) ejection fraction (EF) and LVGLS were measured. Results: The plasma ghrelin levels did not significantly differ between groups. (1067 +/- 489 pg/ml vs. 860 +/- 240 pg/ml, P = 0.232). PAH patients had similar LVEF, RVFAC and TAPSE (all, p>0.05), however PAH group had lower RVGLS, RV free -wall LS and LV GLS (all, p<0.05). Plasma ghrelin level showed no statistically significant correlations with plasma NT-proBNP level, RVGLS, RVLS and LVGLS. Contrarily, plasma NT-proBNP levels showed significant correlations with RVGLS, RVLS and LVGLS (all P < 0.001). Conclusion: Ghrelin might play a role in PAH pathogenesis but current data is insufficient to verify the exact relationship between ghrelin and PAH. The results of this study demonstrate that ghrelin levels are not suited to predict the clinical outcome of PAH since it does not represent the actual clinical situation of the patient.