Diagnostic and endocrine-metabolic significance of serum kallistatin and vasorin in women with polycystic ovary syndrome from Southern Iraq

Objective: Polycystic ovary syndrome (PCOS) is a common endocrine disorder with heterogeneous metabolic and reproductive features. Novel circulating biomarkers may improve phenotypic characterization. This study aimed to compare serum kallistatin and vasorin levels between women with PCOS and healthy controls and to examine their associations with body mass index (BMI), insulin resistance (IR), and reproductive hormones. Methods: This case‑control study enrolled 120 women aged 18–45 years from Southern Iraq: 60 diagnosed with PCOS by Rotterdam criteria and 60 healthy controls. Serum kallistatin and vasorin were measured by enzyme‑linked immunosorbent assay. Metabolic and hormonal parameters were assessed using automated biochemical and electrochemiluminescence immunoassays. Statistical analyses included independent t‑tests, Mann–Whitney U tests, Spearman correlations, and receiver operating characteristic (ROC) curve analysis. Results: Women with PCOS had significantly higher serum kallistatin (3.37 ± 0.85 vs. 2.13 ± 0.96 ng/mL, p < 0.001) and lower serum vasorin (62.72 ± 9.86 vs. 94.92 ± 10.31 pg/mL, p < 0.001) than controls. Kallistatin was significantly higher in those with elevated BMI (3.55 ± 0.82 vs. 2.77 ± 0.67 ng/mL, p = 0.003) and with high IR (3.62 ± 0.85 vs. 2.72 ± 0.40 ng/mL, p < 0.001). Vasorin showed no significant association with BMI or IR but was lower in women with high testosterone (60.27 ± 9.82 vs. 63.53 ± 9.84 pg/mL, p = 0.006). ROC analysis yielded areas under the curve of 0.829 for kallistatin and 0.988 for vasorin. Conclusions: Serum kallistatin and vasorin are altered in PCOS and show distinct association patterns: kallistatin with metabolic features (obesity, insulin resistance) and vasorin with androgen status. These findings support further investigation of both molecules as adjunctive biomarkers, pending validation in independent cohorts.