FGF23 and chronic kidney disease: In CKD, aortic stiffness was not correlated to serum levels of sKlotho (r = 0.148; p = 0.355) (Supplemental Figure S2a), phosphorus (CKD: r = 0.116; p = 0.470), or FGF23 (CKD: r = −0.06; p = 0.712).