title: Review article: the effects of antitumour necrosis factor-α on bone metabolism in inflammatory bowel disease.
abstract: BACKGROUND
  Patients with inflammatory bowel disease (IBD) are at increased risk of osteoporosis. A number of studies have emerged in recent years indicating that tumour necrosis factor (TNF) blockade appears to have a beneficial effect on bone mineral density (BMD) in IBD patients.
  
  
  OBJECTIVE
  To provide a review of the available data regarding the effect of the currently licensed anti-TNF-α therapies on bone metabolism and BMD in IBD patients.
  
  
  METHODS
  A Medline search was performed using the search terms 'infliximab', 'bone metabolism', 'IBD', 'BMD', 'bone markers', 'adalimumab', 'bone disease', 'Crohn's disease' and 'ulcerative colitis'.
  
  
  RESULTS
  Infliximab has a beneficial effect on bone turnover markers in Crohn's disease (CD) patients in the short term. The longest study to date comprising 24 CD patients showed an overall improvement in two bone formation markers - b-alkaline phosphatase (P = 0.022) and osteocalcin (P = 0.008) at 4 months post-treatment. Moreover, the largest study to date comprising 71 CD patients showed significant improvement in sCTx, a bone resorption marker (P = 0.04) at week-8 post-treatment. There is little data looking at the effect of anti-TNF-α therapy on bone metabolism in ulcerative colitis. Moreover, the long-term effects of anti-TNF-α therapy on bone structure and fracture risk in IBD patients are currently not known. The effect of cessation of anti-TNF-α therapy on bone metabolism is also unknown.
  
  
  CONCLUSIONS
  Properly controlled long-term trials are needed to fully evaluate the impact of TNF blockade on bone mineral density.
authors.affiliation: Department of Gastroenterology, Adelaide & Meath Hospital, Tallaght, Dublin, Ireland. sveerappan@rcsi.ie
authors.forename: S G
authors.initials: SG
authors.lastname: Veerappan
authors.forename: C A
authors.initials: CA
authors.lastname: O'Morain
authors.forename: J S
authors.initials: JS
authors.lastname: Daly
authors.forename: B M
authors.initials: BM
authors.lastname: Ryan
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects*; D000911:Antibodies, Monoclonal / Q000494:pharmacology / Q000627:therapeutic use*; D015519:Bone Density / Q000187:drug effects*; D005260:Female; D050723:Fractures, Bone / Q000139:chemically induced / Q000517:prevention & control*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D000069285:Infliximab; D008297:Male; D010024:Osteoporosis / Q000139:chemically induced / Q000188:drug therapy*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000305:Adrenal Cortex Hormones; D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab