Abstract 14572: Diabetic Status Regulates Soluable Receptor for Advanced Glycation End Products Levels in Patients with Atrial Fibrillation Undergoing Coronary Artery Bypass Grafting

Abstract

The receptor for advanced glycation end-products (RAGE), its secretory isoform termed soluble sRAGE and its ligand AGE are induced in response to inflammation and oxidative stress and potentially contribute to the pathogenesis of atrial fibrillation. The present study aimed to examine the levels of AGE, RAGE and sRAGE in 17 diabetic patients (11 male, 6 female) mean age 63.59 years ± 5.79 (SD) and 10 non-diabetic patients (8 male, 2 female) mean age 65.60 years ± 6.39 (SD) all in sinus rhythm undergoing coronary artery bypass grafting (CABG) surgery with cardiopulmonary bypass (CBP). We examined blood serum and right atrial biopsies taken before aortic occlusion and after reperfusion. Serum AGE and sRAGE were assayed by enzyme-linked immunosorbent assay (ELISA). Atrial RAGE mRNA and protein were determined by real-time RT-PCR and Western Analysis respectively. Atrial RAGE mRNA and plasma sRAGE levels were similar in diabetics and non-diabetics before aortic occlusion and reperfusion. Atrial RAGE protein was increased in diabetic patients approximately 2.5-fold (p<0.05) compared to non diabetics. In diabetics post CABG, sRAGE levels increased pre 304.5±27.9 vs. post 441.9±69.5 pg/mL, p<0.05 (mean ± SE) and atrial RAGE protein decreased approximately 50 per cent (p<0.05) compared to pre CABG. Atrial RAGE mRNA did not change. In non diabetics post CABG, sRAGE, atrial RAGE mRNA and protein did not change. Interestingly, similar plasma AGEs were observed in diabetics versus non diabetics pre and post CABG. Higher levels of sRAGE may contribute to the development and progression of vascular complications of diabetes in atrial fibrillation patients post CABG surgery with CBP.