Osteoporosis International

, Volume 19, Issue 3, pp 339–348

Bone turnover and bone collagen maturation in osteoporosis: effects of antiresorptive therapies

  • I. Byrjalsen
  • D. J. Leeming
  • P. Qvist
  • C. Christiansen
  • M. A. Karsdal
Original Article

DOI: 10.1007/s00198-007-0462-5

Cite this article as:
Byrjalsen, I., Leeming, D.J., Qvist, P. et al. Osteoporos Int (2008) 19: 339. doi:10.1007/s00198-007-0462-5

Abstract

Summary

Bone collagen maturation may be important for anti-fracture efficacy as the reduction in risk is only partly explained by a concomitant increase in BMD during anti-resorptive therapy. Different treatments caused diverse profiles in bone collagen degradation products, which may have implications for bone quality.

Introduction

The aim of the present study was to evaluate the effect of different anti-resorptive treatments on bone collagen maturation measured as the ratio between the degradation products of newly synthesized and mature isomerized C-telopeptides of type I collagen.

Methods

Participants were from cohorts of healthy postmenopausal women participating in double blind, placebo-controlled 2-year studies of alendronate, ibandronate, intranasal hormone replacement therapy (HRT), oral HRT, transdermal HRT, or raloxifene (n = 427). The non-isomerized ααCTX and isomerized ββCTX were measured in urine samples obtained at baseline, and after 6, 12, and 24 months of therapy.

Results

Bone collagen maturation measured as the ratio between ααCTX and ββCTX showed that bisphosphonate treatment induced a collagen profile consistent with an older matrix with a 52% (alendronate) and 38% (ibandronate) reduction in the ratio between the two CTX isoforms vs. 3% and 15% with HRT or raloxifene, respectively.

Conclusions

Anti-resorptive treatments had different effects on the endogenous profile of bone collagen maturation. Whether that effect on bone collagen has an impact on bone strength independent on the treatment-dependent effect on BMD should be investigated.

Keywords

Bone qualityBone turnoverCollagenFracture riskMatrix proteins

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2007

Authors and Affiliations

  • I. Byrjalsen
    • 1
  • D. J. Leeming
    • 1
  • P. Qvist
    • 1
  • C. Christiansen
    • 1
  • M. A. Karsdal
    • 1
  1. 1.Nordic Bioscience A/SHerlevDenmark