FGF21 and Osteopenia: High FGF21 level can induce growth retardation, which might be related to the growth hormone resistance in children with CKD.357 Overexpression of FGF21 leads to osteopenia and increased adipogenesis in bone marrow that may contribute to the progress of CKD-mineral and bone disorder (CKD-MBD).256 High FGF21 may also be involved in the neuropsychiatric symptoms in CKD patients.