title: Bone quality of the newest bone formed after two years of teriparatide therapy in patients who were previously treatment-naïve or on long-term alendronate therapy.
abstract: The results of the present study, involving analysis of biopsies from patients who received teriparatide for 2 years and were previously either treatment-naïve or on long-term alendronate therapy, suggest that prior alendronate use does not blunt the favorable effects of teriparatide on bone quality.
  
  
  BACKGROUND
  Examine the effect of 2 years of teriparatide (TPTD) treatment on mineral and organic matrix properties of the newest formed bone in patients who were previously treatment-naïve (TN) or on long-term alendronate (ALN) therapy.
  
  
  METHODS
  Raman and Fourier transform infrared microspectroscopic analyses were used to determine the mineral/matrix (M/M) ratio, the relative proteoglycan (PG) content, and the mineral maturity/crystallinity (MMC; determined by three methods: carbonate content, full width at half height of the v 1 PO4 band [FWHH], and wavelength at maxima of the v 1 PO4 band), as well as collagen maturity (ratio of pyridinoline/divalent cross-links), in paired iliac crest biopsies at trabecular, endosteal, and osteonal surfaces of newly formed bone in postmenopausal osteoporotic women who were previously either TN (n = 16) or receiving long-term ALN treatment (n = 24).
  
  
  RESULTS
  Trabecular M/M ratio increased and matrix content decreased significantly in the ALN pretreated group. Collagen maturity decreased in both patient groups. Endosteal M/M ratio increased significantly in the TN group. Trabecular M/M ratio was higher at endpoint in the ALN pretreated group than in the TN group. Overall, no changes from baseline were observed in PG content, except that PG content was higher in the ALN pretreated group than in the TN group at endosteal surfaces at endpoint. The ability of TPTD treatment to reduce MMC in both patient groups and at the different bone surfaces depended on the measurement tool (relative carbonate content or wavelength at maxima of the v 1 PO4 band). None of the changes in MMC were different between the two patient groups.
  
  
  CONCLUSIONS
  The results suggest some favorable impact of TPTD on bone mineral and organic matrix properties of in situ forming bone in terms of increased initial mineralization and decreased MMC and collagen maturity. Moreover, prior long-term ALN administration may have only limited influence on these properties in bone newly formed after 2 years of TPTD treatment.
authors.affiliation: Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK, AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Hofstetter
authors.forename: S
authors.initials: S
authors.lastname: Gamsjaeger
authors.forename: F
authors.initials: F
authors.lastname: Varga
authors.forename: H
authors.initials: H
authors.lastname: Dobnig
authors.forename: J J
authors.initials: JJ
authors.lastname: Stepan
authors.forename: H
authors.initials: H
authors.lastname: Petto
authors.forename: I
authors.initials: I
authors.lastname: Pavo
authors.forename: K
authors.initials: K
authors.lastname: Klaushofer
authors.forename: E P
authors.initials: EP
authors.lastname: Paschalis
mesh_terms: D000368:Aged; D019386:Alendronate / Q000008:administration & dosage / Q000627:therapeutic use; D001706:Biopsy; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001857:Bone Matrix / Q000187:drug effects; D002113:Calcification, Physiologic / Q000187:drug effects*; D004334:Drug Administration Schedule; D057915:Drug Substitution; D005260:Female; D006801:Humans; D007085:Ilium / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D013059:Spectrum Analysis, Raman / Q000379:methods; D019379:Teriparatide / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D050071:Bone Density Conservation Agents; D019379:Teriparatide; D019386:Alendronate