Serum Thiol/Disulfide Homeostasis and Endocan Levels in Patients Who Underwent Diagnostic Exercise Electrocardiography Test

Abstract

Introduction: Inflammation and oxidative stress are associated with increased risk of cardiovascular diseases. Parameters derived from exercise electrocardiography (ECG) test, such as Duke treadmill score and heart rate recovery (HRR), have prognostic importance and can be used to predict cardiovascular risk. Endocan and thiol/disulfide homeostasis are emerging biomarkers that reflect the inflammatory and oxidative status. The aim of this study was to investigate serum thiol/disulfide homeostasis and endocan levels in an exercise ECG testing patient cohort and to evaluate the association of these markers with Duke treadmill score and HRR. Patients and Methods: Patients who underwent diagnostic exercise ECG test were divided into two groups according to Duke treadmill score and HRR. Serum endocan levels and thiol/disulfide homeostasis were compared between high and low/intermediate Duke treadmill score groups and blunted and normal HRR groups. Results: Serum endocan levels were similar between the groups according to Duke treadmill score and HRR. Thiol/disulfide ratio was significantly lower in patients with blunted HRR than in those with normal HRR. Serum native thiol levels, total thiol levels, and total thiol/disulfide ratio were significantly elevated in patients with a high Duke treadmill score than in those with low/intermediate Duke treadmill score. Native thiol levels and total thiol levels were significantly correlated with Duke treadmill score. Multivariate regression analysis revealed that hypertension and diabetes were independent predictors of blunted HRR, whereas hypertension and low endocan levels were those of low/intermediate Duke treadmill score. Conclusion: Serum thiol levels are correlated with Duke treadmill score, and low endocan levels are associated with low/intermediate Duke treadmill score.