title: Effects of strontium ranelate and alendronate on bone microstructure in women with osteoporosis. Results of a 2-year study.
abstract: Strontium ranelate appears to influence more than alendronate distal tibia bone microstructure as assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), and biomechanically relevant parameters as assessed by micro-finite element analysis (μFEA), over 2 years, in postmenopausal osteoporotic women.
  
  
  BACKGROUND
  Bone microstructure changes are a target in osteoporosis treatment to increase bone strength and reduce fracture risk.
  
  
  METHODS
  Using HR-pQCT, we investigated the effects on distal tibia and radius microstructure of strontium ranelate (SrRan; 2 g/day) or alendronate (70 mg/week) for 2 years in postmenopausal osteoporotic women. This exploratory randomized, double-blind trial evaluated HR-pQCT and FEA parameters, areal bone mineral density (BMD), and bone turnover markers.
  
  
  RESULTS
  In the intention-to-treat population (n = 83, age: 64 ± 8 years; lumbar T-score: -2.8 ± 0.8 [DXA]), distal tibia Cortical Thickness (CTh) and Density (DCort), and cancellous BV/TV increased by 6.3%, 1.4%, and 2.5%, respectively (all P < 0.005), with SrRan, but not with alendronate (0.9%, 0.4%, and 0.8%, NS) (P < 0.05 for all above between-group differences). Difference for CTh evaluated with a distance transformation method was close to significance (P = 0.06). The estimated failure load increased with SrRan (+2.1%, P < 0.005), not with alendronate (-0.6%, NS) (between-group difference, P < 0.01). Cortical stress was lower with SrRan (P < 0.05); both treatments decreased trabecular stress. At distal radius, there was no between-group difference other than DCort (P < 0.05). Bone turnover markers decreased with alendronate; bALP increased (+21%) and serum-CTX-I decreased (-1%) after 2 years of SrRan (between-group difference at each time point for both markers, P < 0.0001). Both treatments were well tolerated.
  
  
  CONCLUSIONS
  Within the constraints of HR-pQCT method, and while a possible artefactual contribution of strontium cannot be quantified, SrRan appeared to influence distal tibia bone microstructure and FEA-determined biomechanical parameters more than alendronate. However, the magnitude of the differences is unclear and requires confirmation with another method.
authors: Division of Bone Diseases, Department of Medical Specialties, Geneva University Hospitals and Faculty of Medicine, 1211 Geneva 14, Switzerland. Rene.Rizzoli@unige.ch
authors: R
authors: R
authors: Rizzoli
authors: R D
authors: RD
authors: Chapurlat
authors: J-M
authors: JM
authors: Laroche
authors: M A
authors: MA
authors: Krieg
authors: T
authors: T
authors: Thomas
authors: I
authors: I
authors: Frieling
authors: S
authors: S
authors: Boutroy
authors: A
authors: A
authors: Laib
authors: O
authors: O
authors: Bock
authors: D
authors: D
authors: Felsenberg
mesh_terms: D000368:Aged; D019386:Alendronate / Q000494:pharmacology* / Q000627:therapeutic use; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D020342:Finite Element Analysis; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D009942:Organometallic Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology; D011884:Radius / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D013876:Thiophenes / Q000494:pharmacology* / Q000627:therapeutic use; D013977:Tibia / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D050071:Bone Density Conservation Agents; D009942:Organometallic Compounds; D013876:Thiophenes; C081587:strontium ranelate; D019386:Alendronate