MON-171 Defining Serum Anti-Müllerian Hormone Cut-off Values for Diagnosing Polycystic Ovary Syndrome in the Brazilian Population

Abstract Disclosure: I.F. Machado: None. F.R. Tinano: None. D.P. Di-Matteo: None. V. Calsavara: None. M. Nishi: None. B. Mendonça: None. L.G. Gomes: None. Background: Polycystic ovary syndrome (PCOS) is a common and complex endocrine disorder. Anti-Müllerian hormone (AMH) measurement has gained recognition as a new criteria for diagnosing PCOS due to its correlation with the increased small ovarian follicular number and dysfunction in the syndrome. However, there is a lack of data defining AMH cut-off values specific to the Brazilian population.Objective: To establish age specific and overall AMH cut-off values for diagnosing PCOS in Brazilian women and evaluate its diagnostic performance and metabolic associations. Methods: This cross-sectional study included 64 women with PCOS and 61 controls recruited from a tertiary care center in São Paulo, Brazil. AMH levels were measured using the Elecsys assay. An overall cut-off and age-specific thresholds were determined using the Youden Index, and diagnostic performance was assessed via receiver operating characteristic (ROC) curve analysis. Metabolic and hormonal profiles, including fasting glucose, insulin and lipid parameters, were analyzed for associations with PCOS. Results: The overall AMH cut-off value of 4.2 ng/mL demonstrated an area under the curve (AUC) of 85% (95% CI: 77.8-91.2%), indicating excellent diagnostic performance. Age-specific AMH cut-offs were identified as 3.8 ng/mL for women aged 18-30 years, 2.5 ng/mL for women aged 30-35 years, and 2.0 ng/mL for women over 35 years, with strong diagnostic performance across all age groups.In the overall analysis, AMH levels positively correlated with fasting insulin and triglycerides. AMH levels were positively associated with elevated testosterone in the PCOS group, underscoring its link to hyperandrogenemia.Conclusion: This study establishes the first overall and age-specific AMH cut-offs for diagnosing PCOS in Brazilian women, addressing a critical gap in the literature. The findings underscore AMH's dual role as a diagnostic biomarker and a tool for understanding and managing reproductive and metabolic dysfunctions in PCOS. However, the variability in AMH thresholds across different assays highlights the need for standardization to ensure consistent and reliable clinical application. Further research should validate these cut-offs across diverse populations and explore their prognostic utility for long-term metabolic and cardiovascular outcomes. Presentation: Monday, July 14, 2025