Assessment of Clinical Utility of Assaying FGF-23, Klotho Protein, Osteocalcin, NTX, and Sclerostin in Patients with Primary Hyperparathyroidism

Abstract

The purpose of this study was to assess the clinical usefulness of assaying the fibroblast growth factor (FGF-23), Klotho, osteocalcin, N-terminal telopeptide of type I collagen (NTX), and sclerostin levels in patients with primary hyperparathyroidism (PHPT) as markers of bone damage as well as for surgical treatment success. Seventeen patients with hypercalcemic PHPT and normal kidney function were studied. In all patients, PTH (parathormone), serum calcium, and creatinine were performed before and six months after parathyroidectomy (PTX). The studied group included patients whose PTH and calcium concentrations normalized post-operatively and with confirmed histopathological diagnosis. The control group consisted of nine age-matched healthy volunteers. The PHPT patients had elevated concentrations of FGF-23, osteocalcin, and NTX and reduced levels of sclerostin, as compared to the control group. After PTX, osteocalcin, NTX, and sclerostin levels normalized. The plasma values of FGF-23 decreased significantly, but remained higher than in healthy subjects. Serum Klotho protein levels did not differ significantly in the two groups. These results suggest that osteocalcin and NTX may potentially be considered as markers of PHPT progression. Additionally, serum normalization of osteocalcin, NTX, and sclerostin might be considered as indicators of PTX success. On the other hand, FGF-23 can represent a parameter reflecting the degree of calcium–phosphate imbalance in PHPT patients, but its usefulness in monitoring the effects of PTX requires further research. The clinical utility of assaying Klotho in PHPT remains to be confirmed.

Normocalcemic primary hyperparathyroidism is an early stage of primary hyperparathyroidism according to fibroblast growth factor 23 level

“…Several studies have failed to demonstrate significantly higher FGF23 levels in PHPT patients with normal renal function than in healthy controls as well as any change in FGF23 concentration after parathyroidectomy (12, 16-18). In contrast, other studies showed that increased FGF23 levels observed in PHPT significantly decreased after successful parathyroidectomy (19)(20)(21)(22). Furthermore, to our knowledge, FGF23 levels have never been previously evaluated in the increasingly recognized NPHPT phenotype.…”

Bone Turnover Markers in Response to Ultrasound-Guided Microwave Ablation for Primary Hyperparathyroidism

“…Osteocalcin regulates the regulation of bone resorption, but also the mineralization of the matrix and differentiation of osteoblasts, a mechanism that maintains the normal mineralization of bone, inhibits the mineralization of cartilage and the abnormal hydroxyapatite crystal formation of bone. A study from Poland found that the osteocalcin levels of 17 PHPT patients returned to normal at six months after surgery ( 27 ). In our study, although osteocalcin did not fall into normal ranges in all patients, the median level of osteocalcin significantly decreased from 35 ng/mL to 22 ng/mL, indicating the improvement of bone turnover status.…”

Phosphate Metabolism and Pathophysiology in Parathyroid Disorders and Endocrine Tumors

“…The authors found that 1.25(OH) 2 vitamin D levels correlated with FGF-23 levels both preoperatively and postoperatively, although they could not find any other significant relationship with calcium, phosphate, and PTH. Another recent study has assessed FGF-23 in PHPT patients [ 20 ]. Seventeen hypercalcemic PHPT patients were evaluated before parathyroidectomy and 6 months after surgery.…”