[Plasma level of apelin and carotid atherosclerosis in maintenance hemodialysis patients].

To determine the plasma level of apelin in patients of maintenance hemodialysis (MHD) and to explore the relationship between apelin level and carotid atherosclerosis (AS) in MHD patients.
 Methods: A total of 92 MHD patients and 36 sex- and age-matched healthy subjects were enrolled in this study. The plasma level of apelin was evaluated by radiation immunoassay; serum endothelial injury markers including thrombomodulin, von Willebrand factor (vWF), and CD146, and inflammatory factors including high sensitive C-reactive protein (hsCRP), IL-6 and TNF-α were determined by ELISA. Common Carotid arteries intima media thickness (CCA-IMT), cross-sectional calculated intima-media area (cIM area) area and atherosclerotic plaque were measured by non-invasive high-resolution B-mode ultrasonography.
 Results: The plasma levels of apelin was significantly decreased in MHD patients compared with healthy subjects (P<0.01), accompanied with elevated plasma levels of thrombomodulin, vWF, CD146, hsCRP, IL-6 and TNF-α (all P<0.01). The plasma levels of apelinin in MHD patients with carotid artery plaques were obviously lower than those without plaques [(43.16±10.12) pg/mL vs (61.43±16.25) pg/mL, P<0.01]. Plasma level of apelin was inversely related with CCA-IMT and cIM area (r=-0.355 and r=-0.297 respectively, all P<0.01). Multiple stepwise regression analysis showed that plasma level of apelin was an independent risk factor for CCA-IMT and cIM area. 
 Conclusion: The plasma apelin in MHD patients might take part in vascular endothelial injury and the progress of atherosclerosis. It plays an important role in the initiation and development of uremia associated atherosclerosis through elevating inflammatory factors including hsCRP, IL-6 and TNF-α levels.