Relationships of Fibroblast Growth Factor-23 Level, Bone Mineral Density and Vascular Calcification in Long-term CAPD patients

초록

Introduction: Fibroblast growth factor-23 (FGF23) is a circulating phosphaturic factor regulating renal phosphate reabsorption and 1(alpha)-hydroxylase activity. It affects bone mineralization and vascular calcifi cation, and it has been reported increased and associated with mortality in the patients with chronic kidney diseases (CKDs) and hemodialysis (HD) patients. We investigated association of FGF23 with bone mineral density and vascular calcifi cation in patients with ESRD on CAPD, which is not yet known. Methods: Fasting serum FGF23 levels were measured using a human FGF23 (C-terminal) ELISA assay in 62 subjects with ESRD. Biochemistry including Ca, P, intact PTH, 25(OH) vitamin D3, bone mineral density (BMD), and vascular calcifi cation score calculated based on a series of plain X-ray were also measured. Results: FGF23 (RU/ml) concentrations were higher in patients with ESRD in comparison with 15 age-matched normal controls (p < 0.001). FGF23 was correlated with serum phosphorus levels (r = 0.565, p < 0.001), serum BUN (r = 0.644, p < 0.01) and creatinine (r = 0.690, p < 0.01) but not with intact PTH and vitamin D. FGF23 has no relationship with BMD of femur and neck. Vascular calcifi cation score showed correlation with FGF23, Ca x P, and iPHT. It showed signifi cant correlation with P level in multiple regression test. Conclusion: FGF23 is increased in CAPD patients in relation with phosphate homoeostasis. The relationship between FGF23 and BMD was not demonstrated. Vascular calcifi cation was severe in the patients with high FGF23 but it was independently related with serum P level.