Multivariate regression analysis further revealed that FSH, LH, and LH/FSH are risk factors for PCOS (P < 0.05), while SHBG continues to be identified as a protective factor (HR = 1.01, 95% CI: 1.01-1.02, P < 0.0001) (Supplementary Table S4). Here, SHBG is linked to polycystic ovary syndrome.