Bone turnover and bone collagen maturation in osteoporosis: effects of antiresorptive therapies
- 203 Downloads
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.
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.
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.
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.
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.
KeywordsBone quality Bone turnover Collagen Fracture risk Matrix proteins
Conflict of Interest
Inger Byrjalsen, Diana J Leeming, and Per Qvist are employees of Nordic Bioscience A/S, and Per Qvist , Claus Christiansen, and Morten A Karsdal are stock owners of Nordic Bioscience A/S.
- 1.Dempster DW (2006) Anatomy and functions of the adult skeleton. In: Favus MJ (founding ed) Primer on the metabolic bone diseases and disorders of mineral metabolism, 6th edn. American Society for Bone and Mineral Research, Washington, USA, pp 7–11Google Scholar