CST3 and Abnormal blood ion concentration: As shown in Table 1, this patient had normal liver function, severely impaired renal function (i.e., increased serum BUN, CREA, Cystatin C, and decreased eGFR), hyperglycemia (GLU, 8.41 mmol/L), serum electrolyte disorders (i.e., decreased Cl− and Ca2+, and increased Mg2+, phosphate).