FGF23 and chronic kidney disease: The objectives of this study were to: (1) analyze longitudinal patterns of FGF23 and soluble Klotho, (2) examine predictors of FGF23 and soluble Klotho levels and (3) investigate possible associations between FGF23 and soluble Klotho to surrogate measures of CVD, in a cohort of pediatric non-dialysis CKD patients and renal transplant recipients followed prospectively for 3 years.