title: Risk factors for osteoporosis in Crohn's disease: infliximab, corticosteroids, body mass index, and age of onset.
abstract: BACKGROUND
  We analyzed the characteristics associated with increased risk of osteoporosis in patients with Crohn's disease in Malta.
  
  
  METHODS
  Eighty-three patients with histologically and endoscopically confirmed Crohn's disease underwent a DEXA bone density scan and their phenotypic characteristics were analyzed.
  
  
  RESULTS
  There was a significant association between body mass index and bone mineral density (P = 0.004) and a significant difference in the T scores of patients according to age at diagnosis (Montreal Classification: P = 0.0006) with patients diagnosed <17 years (n = 13) having lower T scores than those diagnosed at older age groups (n = 70). There was a significant difference between the T scores of patients on infliximab (n = 33) and those not on biological therapy (n = 50, P = 0.0058). Patients with high cumulative corticosteroid doses (>10 mg/d for >3 mo, n = 18) had lower bone mineral densities than patients who received smaller corticosteroid doses (P = 0.013). There was however no significant difference in the T scores of patients according to disease location (P = 0.18), disease type (P = 0.64), gender (P = 0.30), and history of ileal resection (P = 0.68). There was also no significant correlation between disease duration and T scores (hip) (P = 0.61).
  
  
  CONCLUSIONS
  Low body mass index, early disease onset, high corticosteroid doses and, anti-tumor necrosis factor α therapy are associated with increased risk of osteoporosis. Lower T scores in patients on infliximab occur as patients receiving this therapy have more severe inflammation, which is associated with elevated osteoclastogenic factors, rather than as a side-effect of the anti-tumor necrosis factor-α therapy.
authors.affiliation: Division of Gastroenterology, Mater Dei Hospital (Malta), Mellieha, Malta. oldcharm@onvol.net
authors.forename: Neville
authors.initials: N
authors.lastname: Azzopardi
authors.forename: Pierre
authors.initials: P
authors.lastname: Ellul
mesh_terms: D015502:Absorptiometry, Photon; D000305:Adrenal Cortex Hormones / Q000009:adverse effects*; D000328:Adult; D017668:Age of Onset; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D000911:Antibodies, Monoclonal / Q000009:adverse effects*; D015992:Body Mass Index; D015519:Bone Density; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000139:chemically induced / Q000150:complications; D000069285:Infliximab; D008297:Male; D008319:Malta / Q000453:epidemiology; D010024:Osteoporosis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D010641:Phenotype; D011379:Prognosis; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000305:Adrenal Cortex Hormones; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab