Efficacy of simvastatin plus metformin for polycystic ovary syndrome: A meta-analysis of randomized controlled trials

Introduction: The efficacy of simvastatin plus metformin to treat polycystic ovary syndrome (PCOS) remained controversial. Therefore, we conducted this meta-analysis to explore the influence of simvastatin plus metformin versus metformin monotherapy on the treatment of PCOS. Methods: We have searched PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through June 2020 and included randomized controlled trials (RCTs) assessing simvastatin plus metformin versus metformin for PCOS. This meta-analysis was performed using the random-effect model. Results: Five RCTs were included in the meta-analysis. Overall, compared with metformin monotherapy for PCOS, combined treatment with simvastatin plus metformin was associated with significantly reduced total testosterone (mean difference [MD] = -0.31; 95 % confidence interval [CI] = -0.50 to -0.13; P = 0.0009), leuteinizing hormone: follicle stimulating hormone (LH:FSH) ratio (MD = -0.92; 95 % CI = -1.62 to -0.23; P = 0.009) and low-density lipoprotein (LDL) cholesterol (MD = -34.90; 95 % CI = -39.33 to -30.47; P < 0.00001), but spontaneous menses per 6 months, volume of both ovaries, body mass index (BMI) and fasting glucose were found to be similar between two groups. Conclusions: Combined treatment with simvastatin plus metformin was better to treat PCOS than metformin alone as evidenced by significantly reduced total testosterone, LH:FSH ratio and LDL cholesterol. (C) 2020 Published by Elsevier B.V.