s-Klotho levels in our CKD patients were significantly lower (519 ± 183 versus 845 ± 330 pg/mL, P < .0001, Table 3) and FGF23 levels were significantly higher (73 ± 51 versus 36 ± 11 pg/mL, P < 0002, Table 3) than our reference values. Here, FGF23 is linked to chronic kidney disease.