An Increased Serum N-Terminal Telopeptide of Type I Collagen, a Biochemical Marker of Increased Bone Resorption, Is Associated with Infliximab Therapy in Patients with Crohn's Disease

Dig Dis Sci. 2016 Jan;61(1):99-106. doi: 10.1007/s10620-015-3838-y. Epub 2015 Aug 8.


Background: Osteopenia and osteoporosis are considered to be extra-intestinal manifestations of inflammatory bowel disease (IBD). Anti-tumor necrosis factor (TNF)-α biologics have been introduced as novel medications for an active IBD. However, it is still not well documented whether anti-TNF-α affects the frequency of bone loss or abnormality of bone mineral markers among patients with IBD.

Aims: This study was to investigate the biochemical basis of low bone mineral density (BMD) and increased turnover in IBD during infliximab (IFX) therapy.

Methods: Forty patients with Crohn's disease (CD), 80 patients with ulcerative colitis (UC), and 65 age- and gender-matched controls were included. BMD was measured with dual-energy X-ray absorptiometry, and vitamins K and D were measured as serum undercarboxylated osteocalcin (ucOC) and 1,25-(OH)2D, respectively. Bone formation and resorption were based on measuring bone-specific alkaline phosphatase (BAP) and serum N-terminal telopeptide of type I collagen (NTx), respectively.

Results: Significantly lower BMD was found in patients with UC and CD as compared to controls (P < 0.05). BAP, 1,25-(OH)2D, ucOC, and NTx were significantly higher in CD patients, but not in UC patients as compared to controls (P < 0.05). Further, serum NTx level was significantly higher in CD patients who were receiving IFX as compared to CD patients who were not receiving IFX (P < 0.01).

Conclusions: A lower BMD and higher bone metabolism markers were found in CD patients as compared to controls or UC patients. A significant increased serum level of NTx, a biochemical marker of increased bone resorption, was observed in CD patients during IFX therapy.

Keywords: Bone mineral density; Bone resorption; Inflammatory bowel disease; Infliximab; Osteoporosis.

Publication types

  • Comparative Study

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Anti-Inflammatory Agents / therapeutic use*
  • Biomarkers / blood
  • Bone Density / drug effects
  • Bone Resorption / blood*
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects*
  • Bone and Bones / metabolism
  • Case-Control Studies
  • Colitis, Ulcerative / complications
  • Colitis, Ulcerative / diagnosis
  • Colitis, Ulcerative / drug therapy*
  • Collagen Type I / blood*
  • Crohn Disease / blood
  • Crohn Disease / diagnosis
  • Crohn Disease / drug therapy*
  • Female
  • Gastrointestinal Agents / therapeutic use*
  • Humans
  • Infliximab / therapeutic use*
  • Male
  • Middle Aged
  • Osteogenesis / drug effects
  • Peptides / blood*
  • Prospective Studies
  • Time Factors
  • Treatment Outcome
  • Up-Regulation


  • Anti-Inflammatory Agents
  • Biomarkers
  • Collagen Type I
  • Gastrointestinal Agents
  • Peptides
  • collagen type I trimeric cross-linked peptide
  • Infliximab