title: Risk factors for low bone mineral density in children and young adults with Crohn's disease.
abstract: OBJECTIVE
  Low bone mineral density (BMD) is a recognized complication of Crohn's disease (CD). The aim of this study was to identify the risk factors for low BMD in pediatric patients with CD.
  
  
  METHODS
  One hundred nineteen subjects with CD ranging in age from 5 to 25 years were enrolled. BMD of the lumbar spine was measured by dual-energy x-ray absorptiometry. Growth parameters were assessed by examination. Disease-specific variables and use of selected medications were determined by chart review.
  
  
  RESULTS
  Powerful risk factors for low BMD z-score included hypoalbuminemia, exposure to nasogastric tube feeds, total parenteral nutrition, 6-mercaptopurine, and corticosteroids. Corticosteroid dosing at a level >7.5 mg/d, 5000 mg lifetime cumulative dose, or >12 months of lifetime exposure were significant risk factors for low BMD z-score. Weaker but significant associations with low BMD z-scores included measures of disease severity such as pediatric Crohn's disease activity index, hospital admissions, and length of hospital stay. Site and duration of disease were not predictive.
  
  
  CONCLUSIONS
  The presence of several clinically available factors was predictive of poor bone mineral status in this sample of subjects with CD. Hypoalbuminemia, corticosteroid exposure, nasogastric tube feeds, total parenteral nutrition, and 6-mercaptopurine were the most powerful risk factors for low bone mineral status.
authors.affiliation: Division of Gastroenterology and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Semeao
authors.forename: A F
authors.initials: AF
authors.lastname: Jawad
authors.forename: N O
authors.initials: NO
authors.lastname: Stouffer
authors.forename: B S
authors.initials: BS
authors.lastname: Zemel
authors.forename: D A
authors.initials: DA
authors.lastname: Piccoli
authors.forename: V A
authors.initials: VA
authors.lastname: Stallings
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D001827:Body Height; D001835:Body Weight; D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000150:complications* / Q000378:metabolism; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use; D015999:Multivariate Analysis; D010289:Parenteral Nutrition, Total; D012307:Risk Factors; D012709:Serum Albumin / Q000032:analysis
chemical_list: D000305:Adrenal Cortex Hormones; D012709:Serum Albumin; D015122:Mercaptopurine