CST3 and chronic kidney disease: Furthermore, cystatin C concentrations were significantly elevated in the CKD group compared with the control group (CKD group: median 0.7450 mg/L, IQR: 0.2750–1.313; control group: median 0.4550 mg/L, IQR: 0.1950–0.6675; p = 0.0135; Figure 1D).