Fibroblast growth factor 23 is elevated before parathyroid hormone and phosphate in chronic kidney disease

Kidney Int. 2011 Jun;79(12):1370-8. doi: 10.1038/ki.2011.47. Epub 2011 Mar 9.

Abstract

Fibroblast growth factor 23 (FGF23) regulates phosphorus metabolism and is a strong predictor of mortality in dialysis patients. FGF23 is thought to be an early biomarker of disordered phosphorus metabolism in the initial stages of chronic kidney disease (CKD). We measured FGF23 in baseline samples from 3879 patients in the Chronic Renal Insufficiency Cohort study, which is a diverse cohort of patients with CKD stage 2-4. Mean serum phosphate and median parathyroid hormone (PTH) levels were in the normal range, but median FGF23 was markedly greater than in healthy populations, and increased significantly with decreasing estimated glomerular filtration rate (eGFR). High levels of FGF23, defined as being above 100 RU/ml, were more common than secondary hyperparathyroidism and hyperphosphatemia in all strata of eGFR. The threshold of eGFR at which the slope of FGF23 increased was significantly higher than the corresponding threshold for PTH based on non-overlapping 95% confidence intervals. Thus, increased FGF23 is a common manifestation of CKD that develops earlier than increased phosphate or PTH. Hence, FGF23 measurements may be a sensitive early biomarker of disordered phosphorus metabolism in patients with CKD and normal serum phosphate levels.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Biomarkers / blood
  • Biomarkers / urine
  • Female
  • Fibroblast Growth Factors / blood*
  • Glomerular Filtration Rate
  • Humans
  • Hyperparathyroidism, Secondary / blood*
  • Hyperparathyroidism, Secondary / diagnosis
  • Hyperparathyroidism, Secondary / etiology
  • Hyperparathyroidism, Secondary / physiopathology
  • Hyperparathyroidism, Secondary / urine
  • Hyperphosphatemia / blood*
  • Hyperphosphatemia / diagnosis
  • Hyperphosphatemia / etiology
  • Hyperphosphatemia / physiopathology
  • Hyperphosphatemia / urine
  • Male
  • Middle Aged
  • Parathyroid Hormone / blood*
  • Phosphates / blood*
  • Phosphates / urine
  • Phosphorus, Dietary / metabolism
  • Predictive Value of Tests
  • Prospective Studies
  • Renal Insufficiency, Chronic / blood*
  • Renal Insufficiency, Chronic / complications
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / physiopathology
  • Renal Insufficiency, Chronic / urine
  • Severity of Illness Index
  • Time Factors
  • United States
  • Up-Regulation

Substances

  • Biomarkers
  • PTH protein, human
  • Parathyroid Hormone
  • Phosphates
  • Phosphorus, Dietary
  • Fibroblast Growth Factors
  • fibroblast growth factor 23

Grant support