Abstract
OBJECTIVE: To compare hormonal and metabolic characteristics across Rotterdam polycystic ovary syndrome (PCOS) phenotypes (A-D) and identify key predictors of hyperandrogenism. MATERIAL AND METHODS: In this retrospective cohort study, women with PCOS were classified into four Rotterdam phenotypes. Hormonal and metabolic parameters were assessed in the early follicular phase, and composite indices including HOMA-IR, QUICKI, TG/HDL, and free androgen index (FAI) were calculated. Logistic regression and receiver operating characteristic analysis were used to evaluate predictors of hirsutism. RESULTS: The study included 226 women, with respective phenotype subgroups of: A n=85; B n=29; C n=43; and D n=69. Phenotype A showed the most pronounced hyperandrogenic and metabolic alterations, whereas phenotype D displayed the mildest profile with lower androgen levels and hirsutism scores. Significant differences in insulin resistance and lipid-related indices were observed across phenotypes. FAI was the strongest predictor of hirsutism (area under the curve =0.861), followed by total testosterone and dehydroepiandrosterone sulfate, while sex-hormone binding globulin was inversely associated. CONCLUSION: PCOS phenotypes demonstrate distinct hormonal and metabolic patterns. Phenotype A represents the most metabolically and androgenically severe subgroup, whereas phenotype D is comparatively mild. FAI emerges as the most informative marker for hirsutism, supporting a phenotype-oriented approach to clinical assessment and follow-up in PCOS.