Serum syndecan-1 correlates with coronary artery calcification severity and intradialytic hypotension in elderly hemodialysis patients.

BACKGROUND AND

OBJECTIVES

Cardiovascular disease is the leading mortality cause in elderly maintenance hemodialysis (MHD) patients, driven by coronary artery calcification (CAC). Elevated serum syndecan-1 (SDC1), a biomarker of endothelial glycocalyx degradation, indicates vascular dysfunction. This study explored the cross-sectional associations between serum SDC1, CAC severity, and intradialytic hypotension (IDH) in this population.

MATERIALS AND

METHODS

This cross-sectional study enrolled 88 elderly MHD patients and 30 healthy controls. Serum SDC1 was quantified, and CAC severity was assessed via computed tomography coronary artery calcium scores (CACS). IDH episodes were retrospectively reviewed from 3-month standardized dialysis records. Associations were analyzed using Spearman's correlation and multivariable ordinal logistic regression with a clinically prespecified sequential adjustment strategy. The discriminative stability of SDC1 was internally validated using the bootstrap resampling method.

RESULTS

Serum SDC1 was significantly higher in MHD patients than controls (P < 0.001). SDC1 strongly correlated with CACS (r = 0.75, P < 0.001), increasing progressively across CAC severity strata. After adjusting for demographics, clinical history, and mineral metabolism markers, elevated SDC1 was independently associated with greater CAC severity (Adjusted OR = 1.148, 95% CI 1.096-1.202, P < 0.001). Exploratory ROC analysis yielded a robust bootstrap-validated AUC of 0.920 (95% CI 0.867-0.974). An exploratory SDC1 threshold of 33.5 pg/mL identified a phenotype with higher CAC prevalence (86.9% vs. 7.4%, P < 0.001) and more frequent IDH episodes (P < 0.001).

CONCLUSIONS

Elevated serum SDC1 is independently associated with CAC severity and IDH incidence in elderly MHD patients. These findings suggest that SDC1, reflecting endothelial glycocalyx degradation, may serve as a potential indicator of vascular and hemodynamic instability. However, its exploratory role in risk assessment requires further prospective validation in independent cohorts before clinical application.