title: Plasma levels of fibroblast growth factor-23 and mineral metabolism in diabetic and non-diabetic patients on chronic hemodialysis.
abstract: OBJECTIVE
  Fibroblast growth factor (FGF) 23 is a circulating factor that regulates phosphate (P) metabolism. Since higher P levels are associated with vascular calcification, we examined the role of serum FGF-23 levels in P metabolism and vascular calcification in hemodialysis (HD) patients with and without diabetes mellitus (DM).
  
  
  METHODS
  Chronic HD patients with DM (n = 39) and without DM (n = 50) were enrolled. Serum samples were obtained before the start of dialysis sessions, and the FGF-23 levels were determined by enzyme-linked immunosorbent assay. Abdominal computed tomography (CT) scan was performed, and the aortic calcification index (ACI) was determined by one examiner, blinded to the patient characteristics. Measurements of bone mineral density (BMD) were performed at the time of ACI estimation.
  
  
  RESULTS
  Log plasma FGF-23 levels were higher in non-DM (3.74 +/- 0.71 pg/ml) than in DM (3.35 +/- 0.74 pg/ml) patients. The log FGF-23 correlated positively with serum creatinine (r = 0.424, P < 0.0001), albumin (r = 0.225, P = 0.0337), Ca (r = 0.392, P = 0.0001), P (r = 0.735, P < 0.0001), and Ca x P product (r = 0.780, P < 0.0001). There were negative correlations between log FGF-23 and age (r = -0.208, P = 0.0497), glucose (r = -0.231, P = 0.0294), and CRP (r = -0.222, P = 0.0359). Multiple regression analyses were performed to explore the correlations between plasma FGF-23 and other factors associated with vascular calcification in all HD patients. Independent variables were selected based on the results of univariate analyses. The significant factors associated with FGF-23 in HD patients were age, serum levels of creatinine, albumin, glucose, Ca, P, and Ca x P product. Plasma FGF levels did not correlate significantly with either ACI or BMD in these patients.
  
  
  CONCLUSIONS
  Our findings indicate that the plasma FGF-23 level is associated with calcium-phosphate metabolism disorders, but not with aortic calcification, in both non-DM and DM patients on chronic HD. In addition, plasma FGF-23 is associated with serum levels of creatinine and albumin. Therefore, the plasma FGF-23 level may provide a reliable marker for Ca and P imbalance and nutritional status in HD patients.
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kojima
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ogawa
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kosaku
authors.initials: K
authors.lastname: Nitta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001018:Aortic Diseases / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015519:Bone Density; D002114:Calcinosis / Q000097:blood; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000097:blood; D011237:Predictive Value of Tests; D012044:Regression Analysis; D006435:Renal Dialysis; D012709:Serum Albumin / Q000378:metabolism; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed
chemical_list: D001786:Blood Glucose; C000717427:FGF23 protein, human; D010710:Phosphates; D012709:Serum Albumin; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D003404:Creatinine; D002118:Calcium
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