High Baseline SHBG, as an Independent Predictor, Was Associated With High Ovulation: a Secondary Analysis of PCOSAct

Abstract Background: Sex hormone-binding globulin (SHBG) is related to several human systems such as reproductive system and endocrine system. SHBG binds to testosterone and estradiol, therefore we explored ethe role of SHBG on reproductive process. Methods: We carried out secondary analysis of Polycystic Ovary Syndrome and Acupuncture Clinical Trail (PCOSAct) at 21 sites in China, comprising a total of 1000 women with PCOS. A total of 954 women with baseline homocysteine (HCY) were included in the study. Results: Multivariate analysis of predictors of ovulation showed that age, body mass index (BMI), estradiol (E2), total testosterone (T) and SHBG are predictors of ovulation (P=0.0211, 0.0011, 0.0211, 0.0029, 0.0434) whereas luteinizing hormone (LH) to follicle-stimulating hormone (FSH) ratio is negatively correlated with ovulation (P=0.0539). A multivariate logistic regression model (MLRM) of all baseline serum parameters showed the strongest predictive ability for ovulation, followed by MLRM without SHBG. In addition to treatment, baseline SHBG was the strongest single predictor for ovulation. Patients in higher SHBG quartile showed significantly higher ovulation rate (HR=1.138; 95%CI [1.054,1.229], P=0.0009). Notably, significance was observed after adjustment for testosterone (HR=1.139, 95%CI [1.055,1.229], P=0.0009). However, quartiles of T, free testosterone (FT) and E2 all showed no correlation with ovulation. Kaplan-Meier curves showed that high SHBG is positively correlated with high ovulation, conception and pregnancy rates. Conclusions: Higher baseline SHBG is associated with higher ovulation rate and is an independent predictive marker. Trial registration: ClinicalTrials.gov (No. NCT01573858). Registered 10 April 2012, https://clinicaltrials.gov/ct2/show/NCT01573858?cond=NCT01573858&draw=2&rank=1.