Effects of one year daily teriparatide treatment on trabecular bone material properties in postmenopausal osteoporotic women previously treated with alendronate or risedronate

In the present work we examined the effect of teriparatide administration following bisphosphonate treatment on bone compositional properties by Raman and Fourier Transform Infrared Imaging (FTIR) microspectroscopic analysis. Thirty two paired iliac crest biopsies (before and after 1 year teriparatide) from sixteen osteoporotic women previously treated with either Alendronate (ALN) or Risedronate (RIS) and subsequently treated 12 months with teriparatide (TPTD) were analyzed at anatomical areas of similar tissue age in bone forming areas (within the fluorescent double labels). The outcomes that were monitored and reported were mineral to matrix ratio (corresponding to ash weight), mineral maturity (indicative of the mineral crystallite chemistry and stoichiometry, and having a direct bearing on crystallite shape and size), relative proteoglycan content (regulating mineralization commencement), and the ratio of two of the major enzymatic collagen cross-links (pyridinoline/divalent). Significant differences in mineral/matrix, mineral maturity/crystallinity, and collagen cross-link ratio bone quality indices after TPTD treatment were observed, indicating a specific response of these patients to TPTD treatment. Moreover differences between ALN and RIS treated patients at baseline in the collagen cross-link ratio were observed. Since tissue areas of similar tissue age were analyzed, these differences may not be attributed to differences in bone turnover.