Endothelin-2 and Its Association with Uric Acid Levels and Systemic Inflammation: Relevance to Chronic Kidney Disease Progression

Chronic kidney disease (CKD) is associated with chronic inflammation and metabolic dysregulation. While endothelin-1 (ET-1) has been extensively studied, the role of endothelin-2 (ET-2) in CKD remains poorly understood. This cross-sectional study included 76 participants, 12 healthy controls and 64 CKD patients, stratified into three groups based on estimated glomerular filtration rate (eGFR): Group 1 (eGFR ≥ 90 mL/min/1.73 m2), Group 2 (eGFR 45–89 mL/min/1.73 m2), and Group 3 (eGFR 15–44 mL/min/1.73 m2). Serum concentrations of ET-1, ET-2, ET-3, uric acid (UA), and inflammatory markers (hsCRP and IL-6) were measured. ET-2 levels were significantly higher in the advanced CKD group (median 24.49 pg/mL) compared to controls (median 19.32 pg/mL; p = 0.030). No significant differences were observed for ET-1 or ET-3 across groups. ET-2 levels positively correlated with UA (rho = 0.243, p = 0.036), hsCRP (rho = 0.241, p = 0.039), and IL-6 (rho = 0.244, p = 0.038). These findings suggest that ET-2 may represent a potential biomarker reflecting metabolic and inflammatory dysregulation in CKD and highlight its possible relevance in disease severity assessment.