FGF23 and Insulin resistance: BMI, body mass index; BSA, body surface area; eGFR, estimated glomerular filtration rate; FGF23, fibroblast growth factor 23; FMI, fat mass index; HDL, high density lipoprotein cholesterol; HOMA-IR, homeostasis model assessment-insulin resistance; IL-6, interleukin-6; LDL, low density lipoprotein cholesterol; NAE, net acid excretion; PO4, phosphate; PTH, parathyroid hormone; uPRAL, urinary potential renal acid load; Urea-N, 24 h urinary urea nitrogen excretion.