Serum concentrations of insulin were significantly higher in all the PCOS groups than the control group (P < 0.01, Fig. 3a), and the HOMA-IR showed the same tendency (Fig. 3c), although the fasting blood glucose (FBG) didn’t show significant difference among the control and all PCOS groups (P > 0.05, Fig. 3b). Here, INS is linked to polycystic ovary syndrome.