The effects of soy isoflavones on total testosterone and follicle-stimulating hormone levels in women with polycystic ovary syndrome: a systematic review and meta-analysis

Abstract

Objectives

The aims of this systematic review and meta-analysis were to evaluate the effectiveness of soy isoflavones on serum levels of total testosterone (TT) and follicle-stimulating hormone (FSH) in women with polycystic ovary syndrome (PCOS).

Methods

A meta-analysis was performed by searching for relevant randomised controlled trials (RCTs) in several databases. Of the four trials found, the eligibility criteria to evaluate the efficacy of soy isoflavones on serum levels of FSH were met by three trials and of TT by four trials. The Cochrane scale was used to evaluate the risk of bias. Fixed-effects and random-effects models were used to evaluate overall effect. The χ² test (Cochran’s Q test) and the I² index were used to assess the heterogeneity of RCTs.

Results

Our results showed that soy isoflavones significantly decreased TT (weighted mean difference [WMD] − 0.14; 95% confidence interval [CI] − 0.2, −0.02; p = 0.016; I² = 89%, p < 0.001) but had no significant effect on FSH levels (WMD −0.25; 95% CI −0.54, 0.02; p = 0.06; I² = 0%, p = 0.85).

Conclusion

Although the results of this meta-analysis showed that soy isoflavones in women with PCOS decreased TT and had no significant effect on FSH, better and more valid studies are needed to confirm these results.

摘要

目的：评价大豆异黄酮对多囊卵巢综合征（PCOS）患者血清总睾酮（TT）和促卵泡激素（FSH）水平的影响。

方法：通过在多个数据库中搜索相关的随机对照试验（RCTs）进行meta分析, 在发现的四个试验中, 三个试验符合评价大豆异黄酮对血清FSH水平有效性的合格标准, 四个试验符合TT标准；用Cochrane量表评估偏倚的风险, 采用固定效应模型和随机效应模型评价总体效果；采用?²检验（Cochran's Q检验）和I² 指数评价随机对照试验的异质性。

结果：大豆异黄酮显著降低血清总睾酮（TT）（加权平均差WMD-0.14；95%可信区间[CI]-0.2, -0.02；p=0.016；I² =89%, p<0.001）, 但对FSH水平无显著影响（WMD-0.25；95%CI-0.54, 0.02；p=0.06；I² =0%, p=0.85）。

结论：虽然这项荟萃分析结果显示, 多囊卵巢综合征患者的大豆异黄酮降低了TT, 对FSH没有显著影响, 但仍需要更好、更有效的研究来证实这些结果。

Keywords:

• Meta-analysis
• polycystic ovary syndrome
• soy isoflavones
• total testosterone

Acknowledgements

The authors are indebted to the researchers cited in this review for their significant and valuable research.

Disclosure statement

No potential conflict of interest was reported by the author(s).