Serum kisspeptin levels in women with polycystic ovary syndrome: A systematic review and meta-analysis.

[INTRODUCTION] Kisspeptin is a key regulator of the hypothalamic-pituitary-gonadal axis and has been implicated in the pathophysiology of polycystic ovary syndrome (PCOS). However, reported associations between kisspeptin levels and PCOS have been inconsistent.

[MATERIALS AND METHODS] A systematic search of PubMed, Scopus, and Web of Science was performed from inception to August 2025 for studies comparing serum kisspeptin concentrations between PCOS patients and controls. Data extraction was conducted independently by two reviewers. A random-effects meta-analysis was used to calculate pooled standardized mean differences (SMD) with 95% confidence intervals (CI). Heterogeneity was assessed using the Q statistic and I index. Meta-regression was performed to examine BMI as a predictor of kisspeptin levels.

[RESULTS] Twenty studies involving 670 participants were included. Pooled analysis demonstrated significantly higher serum kisspeptin levels in PCOS patients compared with controls (SMD = 0.511; 95% CI: 0.376-0.646; p < 0.001; I = 0%). Meta-regression revealed that BMI significantly moderated the association, with overweight/obese PCOS patients showing the greatest elevation in kisspeptin concentrations (β = 0.756; 95% CI: 0.483-1.029; p < 0.001).

[CONCLUSION] Serum kisspeptin levels are elevated in women with PCOS, particularly among those with overweight/obese BMI, suggesting a possible interaction between metabolic status and reproductive neuroendocrine regulation. These findings support the potential of kisspeptin as a biomarker for PCOS and highlight the need for further research into its mechanistic role and clinical applicability.