title: Associations between fibroblast growth factor 23 and cardiac characteristics in pediatric heart failure.
abstract: BACKGROUND
  In adults with heart failure, elevated levels of fibroblast growth factor 23 (FGF23) are associated with mortality. Data on FGF23 levels in pediatric heart failure are lacking.
  
  
  METHODS
  We conducted a cross-sectional study of 17 healthy children (mean age 13 years) and 20 pediatric patients with heart failure (mean age 12 years) who underwent echocardiography and for whom the following measurements were taken: plasma FGF23 and parathyroid hormone (PTH) and serum phosphate, creatinine and N-terminal prohormone brain natriuretic peptide (NT-proBNP). Symptom severity was assessed with the New York Heart Association and the Ross classification systems.
  
  
  RESULTS
  Of the 20 patients, 11 had dilated cardiomyopathy, four had congenital heart disease, three had hypertrophic cardiomyopathy, one had a failing heart transplant and one had pulmonary hypertension. Mean phosphate levels in these patients were within the reported reference range for healthy children. Median PTH levels were in the normal range in patients and controls. The median FGF23 level was higher in patients versus controls (110.9 vs. 66.4 RU/ml; P = 0.03) and higher in patients on diuretics versus other patients (222.4 vs. 82.1 RU/ml; P = 0.01). Levels of FGF23 and NT-proBNP were directly correlated (r = 0.47, P = 0.04), and patients with greater physical functional impairment had higher FGF23 levels (142.5 in those with moderate-severe limitation vs. 92.8 RU/ml in those with no limitation; P = 0.05). Among patients with dilated cardiomyopathy, higher FGF23 levels were associated with a greater left ventricular end-diastolic diameter (r = 0.63, P = 0.04).
  
  
  CONCLUSIONS
  FGF23 levels are elevated in children with heart failure and are associated with diuretic use, severity of heart failure and left ventricular dilation.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Miami, FL 33136, USA. tisakova@med.miami.edu
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
authors.forename: Jessica
authors.initials: J
authors.lastname: Houston
authors.forename: Laura
authors.initials: L
authors.lastname: Santacruz
authors.forename: Eva
authors.initials: E
authors.lastname: Schiavenato
authors.forename: Gabriel
authors.initials: G
authors.lastname: Somarriba
authors.forename: William G
authors.initials: WG
authors.lastname: Harmon
authors.forename: Steven E
authors.initials: SE
authors.lastname: Lipshultz
authors.forename: Tracie L
authors.initials: TL
authors.lastname: Miller
authors.forename: Paolo G
authors.initials: PG
authors.lastname: Rusconi
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D004232:Diuretics / Q000627:therapeutic use; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006333:Heart Failure / Q000097:blood* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000503:physiopathology; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010710:Phosphates / Q000097:blood; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D014463:Ultrasonography; D015854:Up-Regulation; D016277:Ventricular Function, Left
chemical_list: D015415:Biomarkers; D004232:Diuretics; C000717427:FGF23 protein, human; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D010710:Phosphates; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D003404:Creatinine