HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Marsell, R. Articles by Larsson, T. E Search for Related Content PubMed PubMed Citation Articles by Marsell, R. Articles by Larsson, T. E

Fibroblast growth factor-23 is associated with parathyroid hormone and renal function in a population-based cohort of elderly men

Department of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden¹ Department of Medical Sciences, Uppsala University Hospital, Ing. 70, 3 tr., UAS, 75185 Uppsala, Sweden² Clinical and Molecular Osteoporosis Research Unit, Departments of Clinical Sciences and Orthopaedics, Malmö University Hospital, Lund University, 20502, Malmö, Sweden³ Center for Bone Research at the Sahlgrenska Academy, Department of Internal Medicine, Gothenburg University, 41345, Gothenburg, Sweden and ⁴ Oregon Health and Science University, Portland, Oregon 97239-3098, USA

(Correspondence should be addressed to T E Larsson; Email: tobias.larsson{at}medsci.uu.se)

Objective: Fibroblast growth factor-23 (FGF23) is a circulating factor involved in phosphate (Pi) and vitamin D metabolism. Serum FGF23 is increased at later stages of chronic kidney disease due to chronic hyperphosphatemia and decreased renal clearance. Recent studies also indicate that FGF23 may directly regulate the expression of parathyroid hormone (PTH) in vitro. Therefore, the objective of the current study was to determine the relationship between FGF23, PTH, and other biochemistries in vivo in subjects with no history of renal disease.

Design: Serum biochemistries were measured in a subsample of the population-based Swedish part of the MrOS study. In total, 1000 Caucasian men aged 70–80 years were randomly selected from the population.

Methods: Intact FGF23, Pi, calcium, albumin, estimated glomerular filtration rate (eGFR, calculated from cystatin C), PTH, and 25(OH)D₃ were measured. Association studies were performed using linear univariate and multivariate regression analyses.

Results: The median FGF23 level was 36.6 pg/ml, ranging from 0.63 to 957 pg/ml. There was a significant correlation between log FGF23 and eGFR (r=–0.21; P<0.00001) and log PTH (r=0.13; P<0.001). These variables remained as independent predictors of FGF23 in multivariate analysis. In addition, log PTH (β=0.082; P<0.05) and eGFR (β=–0.090; P<0.05) were associated with log FGF23 in subjects with eGFR>60 ml/min. Only eGFR (β=–0.35; P<0.0001) remained as a predictor of log FGF23 in subjects with eGFR<60 ml/min.

Conclusions: Serum FGF23 and PTH are associated in vivo, supporting recent findings that FGF23 directly regulates PTH expression in vitro. Additionally, eGFR is associated with FGF23 in subjects with normal or mildly impaired renal function, indicating that GFR may modulate FGF23 levels independent of serum Pi.