RNLS and chronic kidney disease: We observed decreased levels of fetuin A (control vs. CKD group: 37.5 vs. 33.2 ng/ml, p = 0.018), and increased concentrations of osteocalcin (control vs. CKD group: 9.1 ± 6.0 vs. 13.6 ± 10.3 ng/ml, p = 0.05), MMP-2 (113.1 ± 75.0 vs. 166.0 ± 129.9 ng/ml, p = 0.045), TIMP-2 (22.1 ± 5.1 vs. 25.4 ± 7,0 ng/ml, p = 0.005) and renalase (251.0 ± 157 vs. 316.1 ± 155.3 ng/ml, p = 0.026).