Circulating Levels of the Heparan Sulfate Proteoglycan Syndecan-4 Positively Associate with Blood Pressure in Healthy Premenopausal Women

Syndecans (SDCs) are transmembrane proteins that are present on most cell types where they play a role in multiple physiological processes, including cell–matrix adhesion and inflammation. Growing evidence suggests that elevated levels of both shed SDC1 and SDC4 are associated with hypertension and cardiovascular diseases, but their relationships with cardiovascular risk factors in healthy individuals are unknown. The primary objective of this study was to investigate whether serum levels of SDC4 and SDC1 were associated with body composition, hemodynamic parameters, pro-inflammatory cytokine concentrations, and urinary noradrenaline and dopamine levels in healthy women (17 African American and 20 European American) between the ages of 20 and 40 years old. Univariate analyses revealed only a significant (p < 0.05) inverse correlation between serum SDC1 and body fat percentage. On the other hand, serum SDC4 was positively correlated with systolic blood pressure, diastolic blood pressure, and urinary levels of noradrenaline and dopamine. Serum SDC4 was also a significant predictor of systolic blood pressure in a multivariate regression model that included fat-free mass and urinary dopamine levels as significant independent variables. The result did not change even adjusting for race. Our findings indicate that SDC4 has an important role in the physiological regulation of blood pressure.