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Fibroblast growth factor-23 is regulated by 1alpha,25-dihydroxyvitamin D.
J Bone Miner Res. 2005 Nov; 20(11):1944-50.JB

Abstract

Serum FGF-23 regulation was studied in patients with hypoparathyroidism or pseudohypoparathyroidism treated with calcitriol. Serum FGF-23 levels changed in parallel in response to changes in serum 1,25-D, suggesting that FGF-23 may be regulated by 1,25-D. In addition, the phosphaturic effect of FGF-23 may be diminished in the absence of PTH action on the kidney.

INTRODUCTION

Fibroblast growth factor (FGF)-23 is a recently described hormone that has been shown to be involved in the regulation of phosphate and vitamin D metabolism. The physiologic role of FGF-23 in mineral metabolism and how serum FGF-23 levels are regulated have yet to be elucidated. Three patients with mineral metabolism defects that allowed for the investigation of the regulation of FGF-23 were studied.

MATERIALS AND METHODS

Patient 1 had postsurgical hypoparathyroidism and Munchausen's syndrome and consumed a pharmacologic dose of calcitriol. Patient 2 had postsurgical hypoparathyroidism and fibrous dysplasia of bone. She was treated with increasing doses of calcitriol followed by synthetic PTH(1-34). Patient 3 had pseudohypoparathyroidism type 1B and tertiary hyperparathyroidism. She underwent parathyroidectomy, which was followed by the development of hungry bone syndrome and hypocalcemia, requiring treatment with calcitriol. Serum FGF-23 and serum and urine levels of mineral metabolites were measured in all three patients.

RESULTS

Patient 1 had an acute and marked increase in serum FGF-23 (70 to 670 RU/ml; normal range, 18-108 RU/ml) within 24 h in response to high-dose calcitriol administration. Patient 2 showed stepwise increases in serum FGF-23 from 117 to 824 RU/ml in response to increasing serum levels of 1alpha,25-dihydroxyvitamin D (1,25-D). Finally, before parathyroidectomy, while hypercalcemic, euphosphatemic, with low levels of 1,25-D (10 pg/ml; normal range, 22-67 pg/ml), and with very high serum PTH (863.7 pg/ml; normal range, 6.0-40.0 pg/ml), patient 3 had high serum FGF-23 levels (217 RU/ml). After surgery, while hypocalcemic, euphosphatemic, and with high serum levels of serum 1,25-D (140 pg/ml), FGF-23 levels were higher than preoperative levels (305 RU/ml). It seemed that the phosphaturic effect of FGF-23 was diminished in the absence of PTH or a PTH effect.

CONCLUSIONS

Serum FGF-23 may be regulated by serum 1,25-D, and its phosphaturic effect may be less in the absence of PTH.

Authors+Show Affiliations

Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892-4320, USA. mc247k@nih.govNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Case Reports
Journal Article

Language

eng

PubMed ID

16234967

Citation

Collins, Michael T., et al. "Fibroblast Growth Factor-23 Is Regulated By 1alpha,25-dihydroxyvitamin D." Journal of Bone and Mineral Research : the Official Journal of the American Society for Bone and Mineral Research, vol. 20, no. 11, 2005, pp. 1944-50.
Collins MT, Lindsay JR, Jain A, et al. Fibroblast growth factor-23 is regulated by 1alpha,25-dihydroxyvitamin D. J Bone Miner Res. 2005;20(11):1944-50.
Collins, M. T., Lindsay, J. R., Jain, A., Kelly, M. H., Cutler, C. M., Weinstein, L. S., Liu, J., Fedarko, N. S., & Winer, K. K. (2005). Fibroblast growth factor-23 is regulated by 1alpha,25-dihydroxyvitamin D. Journal of Bone and Mineral Research : the Official Journal of the American Society for Bone and Mineral Research, 20(11), 1944-50.
Collins MT, et al. Fibroblast Growth Factor-23 Is Regulated By 1alpha,25-dihydroxyvitamin D. J Bone Miner Res. 2005;20(11):1944-50. PubMed PMID: 16234967.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Fibroblast growth factor-23 is regulated by 1alpha,25-dihydroxyvitamin D. AU - Collins,Michael T, AU - Lindsay,John R, AU - Jain,Alka, AU - Kelly,Marilyn H, AU - Cutler,Carolee M, AU - Weinstein,Lee S, AU - Liu,Jie, AU - Fedarko,Neal S, AU - Winer,Karen K, Y1 - 2005/07/18/ PY - 2005/03/08/received PY - 2005/06/08/revised PY - 2005/07/13/accepted PY - 2005/10/20/pubmed PY - 2006/2/28/medline PY - 2005/10/20/entrez SP - 1944 EP - 50 JF - Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research JO - J Bone Miner Res VL - 20 IS - 11 N2 - UNLABELLED: Serum FGF-23 regulation was studied in patients with hypoparathyroidism or pseudohypoparathyroidism treated with calcitriol. Serum FGF-23 levels changed in parallel in response to changes in serum 1,25-D, suggesting that FGF-23 may be regulated by 1,25-D. In addition, the phosphaturic effect of FGF-23 may be diminished in the absence of PTH action on the kidney. INTRODUCTION: Fibroblast growth factor (FGF)-23 is a recently described hormone that has been shown to be involved in the regulation of phosphate and vitamin D metabolism. The physiologic role of FGF-23 in mineral metabolism and how serum FGF-23 levels are regulated have yet to be elucidated. Three patients with mineral metabolism defects that allowed for the investigation of the regulation of FGF-23 were studied. MATERIALS AND METHODS: Patient 1 had postsurgical hypoparathyroidism and Munchausen's syndrome and consumed a pharmacologic dose of calcitriol. Patient 2 had postsurgical hypoparathyroidism and fibrous dysplasia of bone. She was treated with increasing doses of calcitriol followed by synthetic PTH(1-34). Patient 3 had pseudohypoparathyroidism type 1B and tertiary hyperparathyroidism. She underwent parathyroidectomy, which was followed by the development of hungry bone syndrome and hypocalcemia, requiring treatment with calcitriol. Serum FGF-23 and serum and urine levels of mineral metabolites were measured in all three patients. RESULTS: Patient 1 had an acute and marked increase in serum FGF-23 (70 to 670 RU/ml; normal range, 18-108 RU/ml) within 24 h in response to high-dose calcitriol administration. Patient 2 showed stepwise increases in serum FGF-23 from 117 to 824 RU/ml in response to increasing serum levels of 1alpha,25-dihydroxyvitamin D (1,25-D). Finally, before parathyroidectomy, while hypercalcemic, euphosphatemic, with low levels of 1,25-D (10 pg/ml; normal range, 22-67 pg/ml), and with very high serum PTH (863.7 pg/ml; normal range, 6.0-40.0 pg/ml), patient 3 had high serum FGF-23 levels (217 RU/ml). After surgery, while hypocalcemic, euphosphatemic, and with high serum levels of serum 1,25-D (140 pg/ml), FGF-23 levels were higher than preoperative levels (305 RU/ml). It seemed that the phosphaturic effect of FGF-23 was diminished in the absence of PTH or a PTH effect. CONCLUSIONS: Serum FGF-23 may be regulated by serum 1,25-D, and its phosphaturic effect may be less in the absence of PTH. SN - 0884-0431 UR - https://www.unboundmedicine.com/medline/citation/16234967/Fibroblast_growth_factor_23_is_regulated_by_1alpha25_dihydroxyvitamin_D_ L2 - https://doi.org/10.1359/JBMR.050718 DB - PRIME DP - Unbound Medicine ER -