title: DXA-based hip structural analysis of once-weekly bisphosphonate-treated postmenopausal women with low bone mass.
abstract: CONCLUSIONS
  DXA-based hip structural analysis from 947 individuals completing two large osteoporosis clinical trials was pooled and analyzed. Treatment with once-weekly (OW) ALN or OW RIS resulted in significant improvements from baseline in geometric parameters at all three HSA ROIs. Improvements were generally greater with OW ALN than OW RIS.
  
  
  BACKGROUND
  BMD can be altered by changes in distribution and quantity of bone and changes in mineralization. These effects cannot be distinguished with conventional measurements of BMD. Currently, tissue composition is evaluated only by invasive means. Structural geometry of the proximal femur, however, can be measured in vivo by several methods, including dual energy X-ray absorptiometry (DXA) using specialized hip structure analysis (HSA) software.
  
  
  METHODS
  DXA-based HSA was obtained and analyzed in a subset of 947 subjects participating in the Fosamax Actonel Comparison Trials. Data were pooled to evaluate treatment effects on the structural geometry of the proximal femur by once-weekly alendronate (ALN) 70 mg and risedronate (RIS) 35 mg in postmenopausal women with low bone mass.
  
  
  RESULTS
  Both ALN and RIS treatment over 2 years resulted in improvements in HSA-derived geometry at all three HSA regions of interest (ROI). The largest treatment effects were seen at the intertrochanteric ROI. Consistently greater treatment effects were seen with ALN compared with RIS at all three HSA-ROIs.
  
  
  CONCLUSIONS
  HSA offers insight into the potential mechanisms of fracture risk reduction from pharmacologic intervention. In the current study, treatment with once-weekly bisphosphonates resulted in significant improvements in hip geometric parameters.
authors.affiliation: Clinical Research Center of North Texas, 2921 Country Club Road, Ste. 101, Denton, TX 76210, USA. sbonnickcrcnt@verizon.net
authors.forename: S L
authors.initials: SL
authors.lastname: Bonnick
authors.forename: T J
authors.initials: TJ
authors.lastname: Beck
authors.forename: F
authors.initials: F
authors.lastname: Cosman
authors.forename: M C
authors.initials: MC
authors.lastname: Hochberg
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: A E
authors.initials: AE
authors.lastname: de Papp
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D019386:Alendronate / Q000494:pharmacology; D015519:Bone Density / Q000187:drug effects*; D004164:Diphosphonates / Q000494:pharmacology; D012968:Etidronic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000187:drug effects; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D006615:Hip / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging* / Q000188:drug therapy; D000068296:Risedronic Acid; D018570:Risk Assessment
chemical_list: D004164:Diphosphonates; D000068296:Risedronic Acid; D012968:Etidronic Acid; D019386:Alendronate