title: The phosphatonin fibroblast growth factor 23 links calcium-phosphate metabolism with left-ventricular dysfunction and atrial fibrillation.
abstract: OBJECTIVE
  High serum phosphate is linked to cardiovascular morbidity and mortality in the general population. Fibroblast growth factor 23 (FGF-23) is a critical phosphate regulating hormone, potentially reflecting phosphate load better than a single serum phosphate measurement. Recent pioneering echocardiographic studies associated FGF-23 with left-ventricular morphology. However, the association between FGF-23 and left-ventricular function is unknown, prompting us to investigate this relationship in our HOM SWEET HOMe study.
  
  
  RESULTS
  We studied the association between C-terminal FGF-23, coronary artery disease, and left-ventricular function in 885 subjects undergoing elective coronary angiography. Left-ventricular function was assessed with ventriculography. More, pro-brain natriuretic peptide (pro-BNP) plasma levels were measured. The presence of left-ventricular hypertrophy and atrial fibrillation was assessed by electrocardiography. Patients with an ejection fraction <40% had significantly higher FGF-23 levels compared with patients with the ejection fraction >40% (P< 0.001). In multivariable regression analysis, the observed relationship between FGF-23 and left-ventricular function remained significant after adjustment for estimated glomerular filtration rate, presence of left-ventricular hypertrophy, and other confounding variables. In accordance, FGF-23 significantly correlated with pro-BNP plasma levels (r = 0.31; P< 0.001). Prevalent atrial fibrillation was associated with elevated FGF-23 levels, while the presence of coronary artery disease was not.
  
  
  CONCLUSIONS
  Fibroblast growth factor 23 levels are associated with left-ventricular function and atrial fibrillation even in the absence of renal function impairment. Of note, these cross-sectional data cannot prove causality; therefore, future studies will have to discern whether FGF-23 exerts a direct untoward effect on the myocardium, or rather represents an 'innocent bystander' which reflects a high phosphate burden.
authors: Department of Internal Medicine IV, Nephrology and Hypertension,  Saarland University Hospital, Homburg/Saar,  Germany.
authors: Sarah
authors: S
authors: Seiler
authors: Bodo
authors: B
authors: Cremers
authors: Niko M
authors: NM
authors: Rebling
authors: Florian
authors: F
authors: Hornof
authors: Jana
authors: J
authors: Jeken
authors: Sylvie
authors: S
authors: Kersting
authors: Charlotte
authors: C
authors: Steimle
authors: Philipp
authors: P
authors: Ege
authors: Michael
authors: M
authors: Fehrenz
authors: Kyrill S
authors: KS
authors: Rogacev
authors: Bruno
authors: B
authors: Scheller
authors: Michael
authors: M
authors: Böhm
authors: Danilo
authors: D
authors: Fliser
authors: Gunnar H
authors: GH
authors: Heine
mesh_terms: D001281:Atrial Fibrillation / Q000097:blood / Q000209:etiology*; D015415:Biomarkers / Q000378:metabolism; D002130:Calcium Phosphates / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000097:blood / Q000209:etiology*; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000209:etiology; D007674:Kidney Diseases / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000209:etiology*
chemical_list: D015415:Biomarkers; D002130:Calcium Phosphates; C000717427:FGF23 protein, human; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; C020243:calcium phosphate