Effects of a soy-based dietary supplement compared with low-dose hormone therapy on the urogenital system: a randomized, double-blind, controlled clinical trial.

OBJECTIVE: This study aims to compare the effects of a soy-based dietary supplement, low-dose hormone therapy (HT), and placebo on the urogenital system in postmenopausal women. METHODS: In this double-blind, randomized, placebo-controlled trial, 60 healthy postmenopausal women aged 40 to 60 years (mean time since menopause, 4.1 y) were randomized into three groups: a soy dietary supplement group (90 mg of isoflavone), a low-dose HT group (1 mg of estradiol plus 0.5 mg of norethisterone), and a placebo group. Urinary, vaginal, and sexual complaints were evaluated using the urogenital subscale of the Menopause Rating Scale. Vaginal maturation value was calculated. Transvaginal sonography was performed to evaluate endometrial thickness. Genital bleeding pattern was assessed. Statistical analysis was performed using χ(2) test, Fisher's exact test, paired Student's t test, Kruskal-Wallis test, Kruskal-Wallis nonparametric test, and analysis of variance. For intergroup comparisons, Kruskal-Wallis nonparametric test (followed by Mann-Whitney U test) was used. RESULTS: Vaginal dryness improved significantly in the soy and HT groups (P = 0.04). Urinary and sexual symptoms did not change with treatment in the three groups. After 16 weeks of treatment, there was a significant increase in maturation value only in the HT group (P < 0.01). Vaginal pH decreased only in this group (P < 0.01). There were no statistically significant differences in endometrial thickness between the three groups, and the adverse effects evaluated were similar. CONCLUSIONS: This study shows that a soy-based dietary supplement used for 16 weeks fails to exert estrogenic action on the urogenital tract but improves vaginal dryness.

The effect of dietary soy supplementation compared to estrogen and placebo on menopausal symptoms: a randomized controlled trial.

OBJECTIVES: To compare the effects of daily ingestion of dietary soy supplementation, low-dose hormone therapy (HT) and placebo on psychological, somatic and urogenital symptoms in postmenopausal women. STUDY DESIGN: A double-blind, randomized, controlled trial. Sixty healthy, symptomatic, postmenopausal women of 40-60 years of age were allocated to use dietary soy supplementation (containing 90 mg of isoflavone) or HT (1mg estradiol and 0.5mg norethisterone acetate) or placebo. MAIN OUTCOME MEASURES: the Menopause Rating Scale (MRS) was used to assess menopausal symptoms at baseline and after 16 weeks of treatment. Intention-to-treat analyses were performed using the chi-square test, Fisher's exact test, the Kruskal-Wallis non-parametric test and analysis of variance (ANOVA). RESULTS: No statistically significant differences were found between the groups with respect to baseline clinical and sociodemographic characteristics. The psychological, somatic and urogenital symptoms analyzed in the MRS improved during treatment in all the groups, except for urogenital symptoms in the placebo group in which no significant changes were detected. Comparison between groups revealed a statistically significant improvement in somatic symptoms (hot flashes and muscle pain) in the users of HT (-45.6%) and dietary soy supplementation (-49.8%). Urogenital symptoms (vaginal dryness) improved significantly in HT users (-38.6%) and in users of the dietary soy supplementation (-31.2%). There was no statistically significant difference between the groups with respect to overall MRS score or to scores obtained in the psychological symptoms subscale. CONCLUSION: Dietary soy supplementation may constitute an effective alternative therapy for somatic and urogenital symptoms of the menopause.