FGF23 and hyperinsulinism: Winther et al. reported that hyperinsulinemia increased serum FGF-23 levels in patients with type 2 DM.23 Marchelek-Mysliwiec reported that FGF-23 was a significant determinant of insulin resistance in patients with CKD.24 Fernandez-Real et al. determined the relationship between HOMA-IR and FGF-23 in their study on 314 individuals with renal failure.