SHBG and polycystic ovary syndrome: In our study, we found significantly reduced SHBG level in patients with PCOS compared to the control group (37.0 nmol/L (24.7–55.5) vs. 52.9 nmol/L (39.0–67.6); p < 0.05), which determined a higher level of FAI (5.5 (2.8–7.0) vs. 1.6 (1.1–2.3); p < 0.0001).