title: Strontium ranelate reduces the urinary level of cartilage degradation biomarker CTX-II in postmenopausal women.
abstract: OBJECTIVE
  Strontium ranelate significantly decreases the risk of osteoporotic fractures. The objective of the present study was to investigate whether strontium ranelate (2 g/day) also affects cartilage brakedown as measured by urinary marker of cartilage degradation, designated CTX-II.
  
  
  METHODS
  A subgroup of 2617 postmenopausal osteoporotic women (aged 75.7+/-4.4 years) were selected from the TROPOS phase III study on the basis of a urinary sampling reported at each visit during the first three years of the study. When included in TROPOS, they were randomized to strontium ranelate or placebo in a double-blind fashion for 3 years. A calcium and vitamin D supplement was also provided to the subjects during the study. A marker of collagen type II degradation (CTX-II) corrected for urinary creatinine (CTX-II/cr.) was assessed at regular intervals throughout the study in 1310 patients in strontium ranelate group and 1307 patients in placebo group.
  
  
  RESULTS
  The response in CTX-II depended on time (p<0.0001), and this time dependency differed statistically significantly between groups (time x treatment) (p<0.0003). In addition, there was a statistically significant difference between treatments (p<0.0001). The difference in the response of CTX-II/cr. appeared already after three months, with the strontium ranelate-treated subjects having approximately 15-20% lower values than the placebo-treated subjects for the remaining study period (p<0.0001).
  
  
  CONCLUSIONS
  Treatment with strontium ranelate significantly decreases urinary excretion of CTX-II, a marker of cartilage destruction. Further studies are warranted to investigate an effect on cartilage formation and symptoms of osteoarthritis.
authors.affiliation: Center for Clinical and Basic Research a/s, Ballerup Byvej 222, DK-2750 Ballerup, Denmark. pa@ccbr.dk
authors.forename: Peter
authors.initials: P
authors.lastname: Alexandersen
authors.forename: M A
authors.initials: MA
authors.lastname: Karsdal
authors.forename: Per
authors.initials: P
authors.lastname: Qvist
authors.forename: J-Y
authors.initials: JY
authors.lastname: Reginster
authors.forename: Claus
authors.initials: C
authors.lastname: Christiansen
mesh_terms: D015415:Biomarkers / Q000652:urine; D002356:Cartilage / Q000187:drug effects* / Q000473:pathology*; D017326:Clinical Trials, Phase III as Topic; D024043:Collagen Type II / Q000652:urine*; D005260:Female; D006801:Humans; D009942:Organometallic Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy / Q000473:pathology*; D017698:Postmenopause; D013876:Thiophenes / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D015415:Biomarkers; D024043:Collagen Type II; D009942:Organometallic Compounds; D013876:Thiophenes; C081587:strontium ranelate