Serum endothelial lipase, inflammatory and oxidative stress markers in statin-treated patients with coronary artery disease: association with angiographic severity

Endothelial lipase (EL) is involved in HDL metabolism and atherosclerosis. This study evaluated the association of serum EL with inflammatory and oxidative stress markers, and the severity of coronary stenosis in statin-treated patients with coronary artery disease (CAD). In this cross-sectional study, 248 patients undergoing angiography were classified into a non-CAD group ( n = 89) and a CAD group (≥ 50% stenosis, n = 159). Disease severity was quantified using the Gensini score. Fasting serum levels of EL, CRP, malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured. Regression analyses assess associations between biomarkers and CAD risk. Serum EL did not differ significantly between the CAD and non-CAD groups (4.50 ± 2.31ng/ml vs. 4.70 ± 2.85 ng/ml, P = 0.785) or correlate with Gensini stenosis severity (p = 0.475). However, EL demonstrated a significant inverse correlation with systolic (r = − 0.204, p = 0.014) and diastolic (r = − 0.167, P = 0.044) blood pressure. Conversely, serum CRP was significantly elevated in CAD patients (19.79 ± 16.97 mg/l vs. 13.83 ± 11.43 mg/l, P = 0.03) and remained an independent predictor of CAD risk in multivariate logistic regression analysis (OR 1.045, 95% CI 1.007–1.084, P = 0.019) alongside age, male sex, BMI, and waist circumference. MDA and TAC were not independent predictors. In patients on stable statin therapy, circulating EL levels do not correlate with CAD presence or angiographic severity, likely due to uniform pharmacological suppression by statins. However, CRP remains a robust independent biomarker of residual cardiovascular risk in this population.