The relationship between FGF-23 and ghrelin levels in CKD patients: preliminary data.

Background: Fibroblast growth factor (FGF)-23 is a recently discovered phosphaturic hormone that increases in chronic kidney disease (CKD). It has been accepted as a determinant of mortality and a therapeutic target in these patients. Ghrelin is a hormone that has roles in energy and nutrient metabolism. Ghrelin level was found to be increased in CKD patients. This is a controlled study in which the relationship between FGF-23 and ghrelin levels in CKD patients has been studied.

Methods: Three groups were involved: 88 individuals. Dialysis group (DG, 33 patients) including patients on hemodialysis (21 patients) or peritoneal dialysis program (12 patients); predialysis group (PG, 29 patients) consisting of patients with stage-3 CKD; and the control group (CG, 29 individuals) of healthy adults. Serum FGF-23 and ghrelin levels were measured as well as routine biochemical parameters.

Results: FGF-23 levels were similar within the groups (CG: 268±45 pg/mL, PG: 284±94 pg/mL, DG: 259±87 pg/mL, P=0.11). Ghrelin level was higher in the PG group compared with the DG and CG, while DG had higher ghrelin level than the CG (CG: 2.79±0.38 ng/mL, PG: 4.53±1.18 ng/mL, DG: 3.98±0.89 ng/mL). When all groups were studied together; a strong correlation was found between FGF-23 and ghrelin levels. When the analysis was repeated with PG and DG accepted as CKD group; this strong correlation persisted; while it was not true for the CG.

Conclusions: There might be a strong correlation between FGF-23 and ghrelin levels irrespective of the stage of CKD and the dialysis modality. There is need for further studies to clarify the pathophysiological link between these parameters.