H LIEW1,2, M ROBERTS1,2, L MCMAHON1,2
1Department of Renal Medicine, Box Hill, Australia, 2Monash University, Melbourne, Australia
Background: Damage to the endothelial glycocalyx (EG) is an early indicator of vascular damage and a potential marker of endothelial dysfunction. EG damage is detected by biochemical markers and an increase in the perfused boundary region (PBR) in the sublingual capillaries using the novel Glycocheck device.
Aim: We aimed to assess EG damage in patients with kidney disease by measuring the PBR and biochemical markers of EG, and correlating it with markers of endothelial dysfunction (ED) and microalbuminuria.
Methods: Healthy controls, CKD patients (eGFR 15-60mL/min), dialysis patients, and kidney transplant recipients had blood taken for syndecan-1 (EG marker), vascular cell adhesion molecule, VCAM-1 (marker of ED), urine for albumin:creatinine ratio (uACR) and a PBR measurement performed.
Results: Median (interquartile range) ages were 35 (22-69), 71 (37-90), 67 (25-82) and 55 (34-77), p<0.001 years in the control (n=28), CKD (n=33), dialysis (n=33) and transplant (n=30) groups, respectively. Mean eGFR was 89±6, 31±11, 7±4, and 59±14 mL/min (p<0.001) and median uACR was 0.4 (0-2), 37 (0-730), 44 (5-642) and 5 (0-35) mg/mmol (p<0.001), respectively. Serum markers of EG damage and ED were highest in the dialysis group. Median syndecan-1 levels were 26 (10-146), 39 (18-160), 81 (40-530), and 38 (24-67) ng/L (p<0.001), respectively. Mean VCAM levels were 675±211, 1146±468, 1658±552, and 927±254 ng/mL (p<0.001), respectively. There was no difference detected in PBR (2.04±0.31, 2.05±0.28, 2.01±0.35, and 2.06±0.28µm, respectively, p=0.925). Syndecan-1 positively correlated with VCAM (r=0.434, p<0.001) and uACR (r=0.403, p<0.001).
Conclusion: Markers of the EG and ED are closely correlated, and are highest in dialysis patients, followed by CKD and transplant patients compared to controls. No difference in PBR was detected.
Renal Research Fellow