H LIEW1,2, MA ROBERTS1,2, L P MCMAHON1,2,
1Department of Renal Medicine, Box Hill, Melbourne, Victoria; 2Eastern Health Clinical School, Monash University, Melbourne, Victoria
Background: Disruption of the endothelial glycocalyx (EG) is an early indicator of vascular damage and a potential novel marker of endothelial dysfunction in CKD. Biochemical markers and an increased perfused boundary region (PBR) in sublingual capillaries using the novel Glycocheck device may reflect EG damage.
Aim: We aimed to assess correlation of EG damage with endothelial dysfunction (ED) measured by albuminuria and biochemical markers.
Methods: Healthy controls, CKD patients (eGFR 15-60mL/min), and kidney transplant recipients had a Glycocheck measurement performed. Urine and blood were collected for urine albumin:creatinine ratio (ACR), serum hyaluronan, syndecan-1 (markers of EG), von Willebrand factor (vWF) and vascular cell adhesion molecule, VCAM-1 (markers of ED) using commercial ELISA kits.
Results: 24 healthy controls, 26 CKD patients, and 27 transplant recipients were recruited. eGFR negatively correlated with age (r=-0.707, p<0.001), systolic blood pressure (p=-0.529, p<0.001), body mass index (-0.529, p<0.001), hyaluronan (r=-0.521, p<0.001), vWF (p=-0.520, p<0.001), and VCAM (p=-0.540, p<0.001). PBR did not correlate with any markers of EG or ED. Syndecan-1 correlated with vWF (r=0.291, p=0.01), while hyaluronan correlated with vWF (r=0.581, p<0.001), VCAM (r=0.623, p<0.001) and ACR (r=0.435, p<0.005). Hyaluronan, vWF and VCAM all positively correlated with age and systolic blood pressure. In multivariate analysis, significant predictors of (a) hyaluronan were age (β=1.69, p<0.001) and ACR (β=0.250, p<0.001), R2=0.432; (b) vWF were age (β=19.95, p=0.003) and hyaluronan (β=7.24, p<0.001), R2=0.411; and (c) VCAM were hyaluronan (β=2.34, p=0.003) and vWF (β=0.137, p=0.002), R2=0.522. There were no significant predictors of PBR or syndecan-1.
Conclusions: Serum markers of EG damage correlated closely with markers of endothelial damage (vWF, VCAM and ACR and ACR) in this cohort. PBR showed no additional advantage.