title: Fibroblast Growth Factor 23 and Risk of CKD Progression in Children.
abstract: Plasma fibroblast growth factor 23 (FGF23) concentrations increase early in the course of CKD in children. High FGF23 levels associate with progression of CKD in adults. Whether FGF23 predicts CKD progression in children is unknown.
  
  
  
  We tested the hypothesis that high plasma FGF23 is an independent risk factor for CKD progression in 419 children, aged 1-16 years, enrolled in the Chronic Kidney Disease in Children (CKiD) cohort study. We measured plasma FGF23 concentrations at baseline and determined GFR annually using plasma disappearance of iohexol or the CKiD study estimating equation. We analyzed the association of baseline FGF23 with risk of progression to the composite end point, defined as start of dialysis or kidney transplantation or 50% decline from baseline GFR, adjusted for demographics, baseline GFR, proteinuria, other CKD-specific factors, and other mineral metabolites.
  
  
  
  At enrollment, median age was 11 years [interquartile range (IQR), 8-15], GFR was 44 ml/min per 1.73 m2(IQR, 33-57), and FGF23 was 132 RU/ml (IQR, 88-200). During a median follow-up of 5.5 years (IQR, 3.5-6.6), 32.5% of children reached the progression end point. Higher FGF23 concentrations were independently associated with higher risk of the composite outcome (fully adjusted hazard ratio, 2.52 in the highest versus lowest FGF23 tertile; 95% confidence interval, 1.44 to 4.39, P=0.002; fully adjusted hazard ratio, 1.33 per doubling of FGF23; 95% confidence interval, 1.13 to 1.56, P=0.001). The time to progression was 40% shorter for participants in the highest compared with the lowest FGF23 tertile. In contrast, serum phosphorus, vitamin D metabolites, and parathyroid hormone did not consistently associate with progression in adjusted analyses.
  
  
  
  High plasma FGF23 is an independent risk factor for CKD progression in children.
authors: Department of Pediatrics, University of California San Francisco, San Francisco, California.
authors: Anthony A
authors: AA
authors: Portale
authors: Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors: Myles S
authors: MS
authors: Wolf
authors: Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, Florida.
authors: Shari
authors: S
authors: Messinger
authors: Department of Pediatrics, University of California San Francisco, San Francisco, California.
authors: Farzana
authors: F
authors: Perwad
authors: Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
authors: Harald
authors: H
authors: Jüppner
authors: Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri.
authors: Bradley A
authors: BA
authors: Warady
authors: Department of Pediatrics, University of Pennsylvania, Philadelphia, Pennsylvania; and.
authors: Susan L
authors: SL
authors: Furth
authors: Department of Pediatrics, University of California Los Angeles, Los Angeles, California.
authors: Isidro B
authors: IB
authors: Salusky
mesh_terms: D000293:Adolescent; D002648:Child; D018450:Disease Progression; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000503:physiopathology / Q000628:therapy; D018570:Risk Assessment; D012307:Risk Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; D005346:Fibroblast Growth Factors; C097949:1,25-dihydroxyvitamin D; D000089703:Fibroblast Growth Factor-23; C104450:25-hydroxyvitamin D
keywords: CKiD; Confidence Intervals; Demography; Fibroblast Growth Factors; Follow-Up Studies; Minerals; Phosphorus; Renal Insufficiency, Chronic; Vitamin D; adult; child; chronic kidney disease; cohort studies; fibroblast growth factor 23; glomerular filtration rate; humans; iohexol; kidney; kidney transplantation; mineral metabolism; parathyroid hormone; progression of chronic renal failure; proteinuria; renal dialysis; risk factors