FGF23 and left ventricular hypertrophy: Fibroblast growth factor-23 (FGF23), a phosphate-regulating hormone that rises in early CKD, has been causally linked to left ventricular hypertrophy (LVH) via FGFR4 signaling independent of Klotho, as shown in murine models and corroborated in human studies associating elevated FGF23 with increased LVH and mortality [213,214,215].