Trabecular bone microarchitecture after alendronate treatment of osteoporotic women

Curr Med Res Opin. 2005 Feb;21(2):185-94. doi: 10.1185/030079904X20259.

Abstract

Objective: To compare the microarchitecture of iliac crest trabecular bone from women treated for two to three years with alendronate versus that of women treated with placebo.

Research design and methods: Three-dimensional micro-computed tomography (micro-CT; resolution 20 microm) and two-dimensional histomorphometry (resolution 5-7 microm) were used to examine trabecular bone from single transilial biopsies obtained at the completion of clinical trials.

Main outcome measures: Microarchitectural variables, including bone volume, trabecular number, trabecular thickness, and trabecular spacing in specimens from alendronate- and placebo-treated women were examined. Three-dimensional images of trabecular bone from both groups were constructed from CT images. Correlations among variables and between techniques were also calculated.

Results: Eighty-eight specimens were suitable for evaluation by both techniques. As measured by two-dimensional histomorphometry, bone volume fraction (as a proportion of total volume) and trabecular thickness were significantly greater in alendronate specimens, 17.1 +/- 5.5% vs. 13.4 +/- 5.5% (p = 0.0043) and 127 +/- 29 microm vs. 109 +/- 28 microm (p = 0.0090), respectively, and trabecular spacing was significantly smaller, 729 +/- 227 microm vs. 862 +/- 338 microm (p = 0.005). Micro-CT yielded similar findings: bone volume and trabecular number were significantly greater in alendronate specimens: 19.4 +/- 6.2% vs. 16.2 +/- 6.3% (p = 0.0412) and 1.46(+/-) 0.32 vs. 1.31(+/-) 0.33 per mm (p = 0.0346). Two-dimensional and micro-CT measured characteristics correlated strongly with one another, with Pearson product moment correlation coefficients ranging from 0.60 (for trabecular thickness) to 0.83 (for bone volume).

Conclusions: Trabecular microarchitecture of the ilium, whether studied by two- or three-dimensional methods, is better (greater bone volume, greater trabecular thickness, decreased trabecular spacing) after alendronate treatment than after two to three years of treatment with placebo. Bone volume in a trabecular region is strongly correlated to its microarchitecture, suggesting that bone quantity predicts values for these microarchitectural endpoints.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase III
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alendronate / pharmacology*
  • Alendronate / therapeutic use
  • Biopsy
  • Bone Density / drug effects*
  • Bone Resorption / drug therapy
  • Electron Probe Microanalysis
  • Female
  • Humans
  • Ilium / diagnostic imaging
  • Ilium / drug effects
  • Lumbar Vertebrae / diagnostic imaging
  • Lumbar Vertebrae / drug effects*
  • Middle Aged
  • Osteogenesis / drug effects
  • Osteoporosis / drug therapy*
  • Osteoporosis / physiopathology*
  • Placebos
  • Tomography, X-Ray Computed

Substances

  • Placebos
  • Alendronate