Effect of genistein on endothelial function in postmenopausal women: a randomized, double-blind, controlled study

Am J Med. 2003 Apr 15;114(6):470-6. doi: 10.1016/s0002-9343(03)00059-7.

Abstract

Purpose: Genistein, a phytoestrogen found in soybeans, corrects endothelial dysfunction induced by oophorectomy in animals. Using a double-blind, controlled, randomized design, we evaluated its effects on endothelial function in women.

Methods: We enrolled 79 healthy postmenopausal women (mean [+/- SD] age, 56 +/- 4 years) and randomly assigned them to receive continuous estrogen/progestin therapy (n = 26; 17beta-estradiol [1 mg/d] combined with norethisterone acetate [0.5 mg/d]), genistein (n = 27; 54 mg/d), or placebo (n = 26). Brachial artery flow-mediated, endothelium-dependent vasodilation and plasma levels of nitrites/nitrates (a marker of nitric oxide metabolism) and endothelin-1 were measured at baseline and after 1 year of therapy.

Results: Treatment with genistein increased levels of nitrites/nitrates (mean increase, 21 micromol/L; 95% confidence interval [CI]: 15 to 26 micromol/L; P <0.001 vs. placebo); estrogen/progestin therapy caused similar changes (P <0.001 vs. placebo). Plasma endothelin-1 levels decreased following 12 months of genistein (mean decrease, 7 pg/mL; 95% CI: 3 to 10 pg/mL; P <0.001 vs. placebo) and after 12 months of estrogen/progestin (P <0.001 vs. placebo). When compared with placebo, brachial artery flow-mediated dilation was improved by genistein (mean increase, 5.5%; 95% CI: 3.9% to 7.0%; P <0.001) and by estrogen/progestin (P <0.001). There were no significant differences between estrogen and genistein for any of these parameters (all P >0.4).

Conclusion: One year of genistein therapy improves endothelium function in postmenopausal women to a similar extent as does an estrogen/progestin regimen.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Biomarkers / blood
  • Brachial Artery / physiology
  • Double-Blind Method
  • Endothelin-1 / blood
  • Endothelium, Vascular / drug effects*
  • Estradiol / pharmacology
  • Estrogen Replacement Therapy
  • Female
  • Genistein / adverse effects
  • Genistein / pharmacology*
  • Humans
  • Middle Aged
  • Nitrates / blood
  • Nitrites / blood
  • Norethindrone / analogs & derivatives*
  • Norethindrone / pharmacology
  • Norethindrone Acetate
  • Postmenopause / physiology*
  • Time Factors
  • Vasodilation / drug effects

Substances

  • Biomarkers
  • Endothelin-1
  • Nitrates
  • Nitrites
  • Estradiol
  • Norethindrone Acetate
  • Genistein
  • Norethindrone