Glycocalyx injury in adults with nephrotic syndrome: Association with endothelial function.

Background: Glomerulopathy is a group of diseases that affect mainly young adults. Endothelial dysfunction, atherosclerosis, and increased cardiac mortality can complicate the evolution of such patients. However, there is no study evaluating endothelial glycocalyx in this pathology.

Methods: This cross-sectional study included 49 patients with untreated primary nephrotic syndrome that were otherwise healthy. In addition to routine laboratory measurements, syndecan-1, intercellular adhesion molecule-1 (ICAM-1), and e-selectin were measured. Moreover, flow-mediated dilation (FMD) was used as the main endothelial function surrogate.

Results: Of the 49 patients with nephrotic syndrome, 25 (51.0%) were females. The mean age of patients was 39.0±12.1y. FMD was reduced in nephrotic patients in comparison with controls (3.7±1.7 vs. 6.6±1.1%, p<0.001). Nephrotic patients had higher levels of ICAM-1 (616.6±219.7 vs. 356.9±102.0ng/ml, p<0.001) and syndecan-1 (180.3±64.1 vs. 28.2±9.8ng/ml, p<0.001). No significant difference was observed regarding e-selectin (129.9±54.2 vs. 120.2±61.5ng/ml, p=0.489). After adjusting for age and glomerular filtration rate, syndecan-1 was significantly associated with 24-h urinary protein excretion, LDL-cholesterol, HDL-cholesterol, and triglycerides. While age, LDL-cholesterol, and 24-h urinary protein excretion were associated with FMD in the multivariate analysis, when syndecan-1, ICAM-1, and e-selectin were added to the model, only syndecan-1 was independently associated with FMD.

Conclusions: We demonstrated that syndecan-1, a marker of endothelial glycocalyx damage, is increased in patients with nephrotic syndrome and near-normal renal function. Moreover, we determined its association with nephrotic syndrome features and suggest it can have a role in the endothelial dysfunction of these patients.