Spectroscopic markers of bone quality in alendronate-treated postmenopausal women
Comparison of infrared spectroscopic images of sections from biopsies of placebo-treated post-menopausal women and women treated for 3 years with 10 mg/day alendronate demonstrated significant increases in cortical bone mineral content, no alterations in other spectroscopic markers of “bone quality,” but a decrease in tissue heterogeneity.
The material properties of thick sections from iliac crest biopsies of seven alendronate-treated women were compared to those from ten comparably aged post-menopausal women without bone disease, using infrared spectroscopic imaging at ∼7 μm spatial resolution. Parameters evaluated were mineral/matrix ratio, crystallinity, carbonate/amide I ratio, and collagen maturity. The line widths at half maximum of the pixel histograms for each parameter were used as measures of heterogeneity.
The mineral content (mineral/matrix ratio) in the cortical bone of the treated women’s biopsies was higher than that in the untreated control women. Crystallinity, carbonate/protein, and collagen maturity indices were not significantly altered; however, the pixel distribution was significantly narrowed for all cortical and trabecular parameters with the exception of collagen maturity in the alendronate treatment group.
The increases in mineral density and decreased fracture risk associated with bisphosphonate treatment may be counterbalanced by a decrease in tissue heterogeneity, which could impair tissue mechanical properties. These consistent data suggest that alendronate treatment, while increasing the bone mass, decreases the tissue heterogeneity.
KeywordsAlendronate Bone heterogeneity Infrared spectroscopic imaging Osteoporosis
This study was supported by NIH grant AR043125 and Core Center grant AR046121 to A.L.B. and by AR046191 to R.S.W. This investigation was conducted in a facility constructed with support from Research Facilities Improvement Program grant number C06-RR12538-01 from the National Center for Research Resources, National Institutes of Health.
Conflicts of interest
- 15.Tumanov AT, Gunyaev GM, Lyutsau VG, Stepanychev EI (1975) Structure, properties, and tests of carbon-reinforced plastics. Mech Compos Mater 11:167–327Google Scholar
- 16.National Materials Advisory Board Committee on high-performance synthetic fibers for composites; Commission on Engineering and Technical Systems; National Research Council (1992) High-performance synthetic fibers for composites publication NMAB-458. National Academy Press, Washington, DC, pp 49–103Google Scholar
- 29.Keaveny TM, Hayes WC (1993) A 20-year perspective on the mechanical properties of trabecular bone. Transact ASME 115:534–554Google Scholar