The effect of the phytoestrogen genistein and hormone replacement therapy on homocysteine and C-reactive protein level in postmenopausal women

BACKGROUND: The aim of the study was to evaluate the effect, in postmenopausal women, of the phytoestrogen genistein and hormone replacement therapy (HRT) on circulating two independent factors of cardiovascular risk: homocysteine and C-reactive protein (CRP). METHODS: Ninety healthy postmenopausal women, from 50 to 60 years of age, were randomly assigned to receive genistein (n = 30; 54 mg/die) or continuous combined estrogen/progestin therapy (17-beta-estradiol 1 mg plus norethisterone acetate 0.5 mg) or placebo. Plasma homocysteine and serum CRP were measured at baseline and after 6 months of treatment. RESULTS: In the genistein group, plasma homocysteine and serum CRP showed no statistically significant difference from baseline (homocysteine: 11.36 +/- 0.39 micromol/l; CRP: 1.73 +/- 0.31 mg/l) to 6 months treatment (homocysteine: 10.72 +/- 0.46 micromol/l; CRP: 2.13 +/- 0.45 mg/l), without any significant difference versus the placebo group (homocysteine: 11.25 +/- 0.43 micromol/l; CRP: 1.74 +/- 0.22 mg/l). In the HRT group there was a slight, but not significant reduction, of plasma homocysteine mean value from baseline (11.21 +/- 0.44 micromol/l) to 6 months treatment (10.45 +/- 0.38 micromol/l); whereas CRP mean value at the end of treatment (3.30 +/- 0.55 mg/l) was significantly higher from baseline (1.61 +/- 0.25 mg/l) (P < 0.01). However, after 6 months, no significant difference existed with the other two groups. CONCLUSIONS: The phytoestrogen genistein, after 6 months treatment, does not modify the independent cardiovascular risk linked to circulating homocysteine or CRP level. Our experience confirms critical increase of CRP serum level after HRT treatment, but not plasma homocysteine significant variation.