EDN1 and chronic kidney disease: We detected higher serum ET-1 and renalase levels in the CKD(+) group than in the CKD(−) group (1.95 ± 0.77 vs. 1.62 ± 0.76 pg/ml, P < 0.001 for ET-1; 46.8 ± 17.1 vs. 33.9 ± 9.9 ng/ml, P < 0.001 for renalase).