Trabecular bone microarchitecture after alendronate treatment of osteoporotic women.
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.


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.


METHODS
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.
Recker
R
R
Osteoporosis Research Center, Creighton University, Omaha, NE 68131-2137, USA. rrecker@creighton.edu
Masarachia
P
P
Santora
A
A
Howard
T
T
Chavassieux
P
P
Arlot
M
M
Rodan
G
G
Wehren
L
L
Kimmel
D
D
D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000494:pharmacology* / Q000627:therapeutic use; D001706:Biopsy; D015519:Bone Density / Q000187:drug effects*; D001862:Bone Resorption / Q000188:drug therapy; D004577:Electron Probe Microanalysis; D005260:Female; D006801:Humans; D007085:Ilium / Q000000981:diagnostic imaging / Q000187:drug effects; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects*; D008875:Middle Aged; D010012:Osteogenesis / Q000187:drug effects; D010024:Osteoporosis / Q000188:drug therapy* / Q000503:physiopathology*; D010919:Placebos; D014057:Tomography, X-Ray Computed
D010919:Placebos; D019386:Alendronate