Objective: This systematic review and meta-analysis aimed to summarize the available evidence regarding circulating kisspeptin and anti-müllerian hormone (AMH) and the homeostasis model assessment of insulin resistance (HOMA-IR) index in adolescents and women with and without polycystic ovary syndrome (PCOS).Method: We performed a comprehensive literature search in Medline, Embase, Cochrane, Scopus, and Web of Science for studies evaluating circulating kisspeptin levels in women with and without PCOS published until September 24th, 2020. Coprimary outcomes were the HOMA-IR index and AMH. The quality of included studies was assessed using the Newcastle-Ottawa Scale. Random-effects models were used to estimate outcomes, and effects reported as mean difference (MD) or standardized MD (SMD) and their 95% confidence interval (CI). The systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as number CRD42020205030.
Results: We evaluated 18 studies including, 1,282 PCOS cases and 977 controls. Participants with PCOS were younger (MD=-2.38 years, 95%CI -4.32 to -0.44), with higher BMI (MD=1.16, 95% CI 0.54 to 1.78), waist-to-hip ratio (MD=0.04, 95%CI 0.02 to 0.05), circulating kisspeptin (SMD=1.15, 95%CI 0.68 to 1.62), luteinizing hormone (SMD=1.29, 95%CI 0.76 to 1.83), AMH (SMD=0.97, 95%CI 0.60 to 1,34), total testosterone (SMD=2.48, 95%CI 1.73 to 3.23), free testosterone (SMD=1.37, 95%CI 0.56 to 2.17), and dehydroepiandrosterone sulfate (SMD=0.72, 95%CI 0.32 to 1.13) levels, and Ferriman-Galweg score (SMD = 5.08, 95%CI 2.76 to 7.39), and lower sex hormone-binding globulin level (SMD=-1.34, 95%CI -2.15 to -0.52). Besides, participants with PCOS had higher HOMA-IR index (SMD=0.76, 95%CI 0.35 to 1.17), and circulating insulin (SMD=0.75, 95%CI 0.30 to 1.19), leptin (SMD=2.82, 95%CI 1.35 to 4.29), and triglycerides (SMD=2.15, 95%CI 1.08 to 3.23) levels than participants without the syndrome. The meta-regression did not identify significant factors influencing circulating kisspeptin.
Conclusion:Patients with PCOS showed higher kisspeptin, LH, insulin, AMH, and androgen levels and HOMA-IR index, and lower sex hormone-binding globulin levels than those without the syndrome.