Apelin: A potential link between inflammation and cardiovascular disease in end stage renal disease patients

Background and objectives. Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis patients. Increasing evidence suggests a role for apelin in the pathology of the cardiovascular system. In the present study, the plasma level of apelin was studied in patients with hemodialysis to assess the effect of renal transplantation and dialysis session on plasma apelin and whether circulating apelin levels reflect cardiovascular homeostasis and inflammation in these patients. Patients and methods. Plasma apelin, high sensitive CRP (hsCRP) and IL-6 levels were investigated in 30 end stage renal disease (ESRD) patients on maintenance hemodialysis (HD), a group of 15 HD patients scheduled for renal transplantation and a group of 15 HD patients on maintenance HD, as well as ten healthy volunteer subjects who served as controls. An echocardiography was performed for all subjects. Results. Plasma apelin levels were significantly lower in hemodialyzed patients compared to controls. Plasma apelin was also found to be positively correlated with left ventricular end systolic dimension (LVESD), left ventricular end diastolic dimension (LVEDD), interventricular septum (IVS), right ventricle (RV), left atrium (LA), Aorta (Ao), while, it was negatively correlated with hsCRP and IL-6 in ESRD patients. Regarding the effect of hemodialysis on plasma apelin levels, no significant effect was found after a single hemodialysis session, while levels increased significantly in the early post-transplant period. Conclusions. Apelin is related to echocardiographic features and inflammatory markers in hemodialyzed patients. Apelin may provide a mechanism for systemic inflammatory monitoring and adaptive regulation of cardiovascular function.