title: Fibroblast growth factor 23 contributes to diminished bone mineral density in childhood inflammatory bowel disease.
abstract: BACKGROUND
  Diminished bone mineral density (BMD) is of significant concern in pediatric inflammatory bowel disease (IBD). Exact etiology is debatable. The recognition of fibroblast growth factor 23 (FGF23), a phosphaturic hormone related to tumor necrosis factor alpha (TNF-α) makes it plausible to hypothesize its possible relation to this pathology.
  
  
  METHODS
  In this follow up case control study, BMD as well as serum levels of FGF23, calcium, phosphorus, alkaline phosphatase, creatinine, parathyroid hormone, 25 hydroxy vitamin D3 and 1, 25 dihydroxy vitamin D3 were measured in 47 children with IBD during flare and reassessed in the next remission.
  
  
  RESULTS
  Low BMD was frequent during IBD flare (87.2%) with significant improvement after remission (44.7%). During disease flare, only 21.3% of patients had vitamin D deficiency, which was severe in 12.8%. During remission, all patients had normal vitamin D except for two patients with Crohn's disease (CD) who remained vitamin D deficient. Mean value of serum FGF23 was significantly higher among patients with IBD during flare compared to controls. It showed significant improvement during remission but not to the control values. 1, 25 dihydroxy vitamin D3, FGF23, serum calcium and urinary phosphorus were significant determinants of BMD in IBD patients.
  
  
  CONCLUSIONS
  We can conclude that diminished BMD in childhood IBD is a common multifactorial problem. Elevated FGF23 would be a novel addition to the list of factors affecting bone mineral density in this context. Further molecular studies are warranted to display the exact interplay of these factors.
authors.affiliation: Department Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt. moshodhod@yahoo.com
authors.forename: Mostafa Abdel-Aziz
authors.initials: MA
authors.lastname: El-Hodhod
authors.forename: Ahmad Mohamed
authors.initials: AM
authors.lastname: Hamdy
authors.forename: Amal Ahmed
authors.initials: AA
authors.lastname: Abbas
authors.forename: Sherine George
authors.initials: SG
authors.lastname: Moftah
authors.forename: Alhag Ahmed Mohamed
authors.initials: AA
authors.lastname: Ramadan
mesh_terms: D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000378:metabolism / Q000503:physiopathology; D003424:Crohn Disease / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000502:physiology*; D005500:Follow-Up Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D010024:Osteoporosis / Q000503:physiopathology*; D010281:Parathyroid Hormone / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014807:Vitamin D / Q000378:metabolism
chemical_list: C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D014409:Tumor Necrosis Factor-alpha; D014807:Vitamin D; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D002118:Calcium