title: The effect of soy isoflavone on bone mineral density in postmenopausal Taiwanese women with bone loss: a 2-year randomized double-blind placebo-controlled study.
abstract: The treatment of 300-mg/day isoflavones (aglycone equivalents) (172.5 mg genistein + 127.5 mg daidzein) for 2 years failed to prevent lumbar spine and total proximal femur bone mineral density (BMD) from declining as compared with the placebo group in a randomized, double-blind, two-arm designed study enrolling 431 postmenopausal women 45-65 years old.
  
  
  BACKGROUND
  This study evaluated the effects of soy isoflavones on bone metabolism in postmenopausal women.
  
  
  METHODS
  Four hundred and thirty-one women, aged 45-65 years, orally consumed 300-mg/day isoflavones (aglycone equivalents) or a placebo for 2 years in a parallel group, randomized, double-blind, two-arm study. Each participant also ingested 600 mg of calcium and 125 IU of vitamin D(3) per day. The BMD of the lumbar spine and total proximal femur were measured using dual-energy X-ray absorptiometry at baseline and every half-year thereafter. Serum bone-specific alkaline phosphatase, urinary N-telopeptide of type 1 collagen/creatinine, and other safety assessments were examined regularly.
  
  
  RESULTS
  Two hundred out of 217 subjects in the isoflavone group and 199 out of 214 cases in placebo group completed the treatment. Serum concentrations of isoflavone metabolites, genistein and daidzein, of the intervention group were remarkably elevated following intake of isoflavones (p < 0.001). However, differences in the mean percentage changes of BMD throughout the treatment period were not statistically significant (lumbar spine, p = 0.42; total femur, p = 0.39) between the isoflavone and placebo groups, according to the generalized estimating equation (GEE) method. A significant time trend of bone loss was observed at both sites as assessed by the GEE method following repeated measurement of BMD (p < 0.001). Differences in bone marker levels were not significant between the two treatment groups.
  
  
  CONCLUSIONS
  Treatment with 300-mg/day isoflavones (aglycone equivalents) failed to prevent a decline in BMD in the lumbar spine or total femur compared with the placebo group.
authors: Division of Geriatric Research, Institute of Population Health Sciences, National Health Research Institutes, Taipei, Taiwan. tytai@tjci.org.tw
authors: T Y
authors: TY
authors: Tai
authors: K S
authors: KS
authors: Tsai
authors: S T
authors: ST
authors: Tu
authors: J S
authors: JS
authors: Wu
authors: C I
authors: CI
authors: Chang
authors: C L
authors: CL
authors: Chen
authors: N S
authors: NS
authors: Shaw
authors: H Y
authors: HY
authors: Peng
authors: S Y
authors: SY
authors: Wang
authors: C H
authors: CH
authors: Wu
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D005269:Femur / Q000503:physiopathology; D019833:Genistein / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007529:Isoflavones / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000503:physiopathology; D048789:Phytoestrogens / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D010919:Placebos; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D004338:Drug Combinations; D007529:Isoflavones; D048789:Phytoestrogens; D010919:Placebos; C004742:daidzein; D019833:Genistein