Increased Ratio of Total Testosterone to Dihydrotestosterone May Predict an Adverse Metabolic Outcome in Polycystic Ovary Syndrome

Background: Androgen excess may correlate with metabolic risk in polycystic ovary syndrome (PCOS). The aim of the study was to determine the role of total testosterone to dihydrotestosterone (TT/DHT) ratio in assessing the adverse metabolic outcome in PCOS. Methods: This cross-sectional study encompassed 40 PCOS women recruited on the basis of revised Rotterdam criteria 2003, and 40 age-matched control subjects. TT, sex hormone binding globulin (SHBG) and insulin levels were measured by chemiluminescent microparticle immunoassay (CMIA) while DHT by enzyme-linked immunosorbent assay (ELISA). In addition, TT/DHT ratio, free androgen index (FAI), and insulin resistance (IR) by homeostatic model of assessment of insulin resistance (HOMA-IR) were calculated. Results: TT/DHT ratio was significantly higher in PCOS group than control group (P < 0.001). No significant difference was found for DHT (P = 0.261). PCOS patients had significantly higher TT (0.69 +/- 0.26 vs. 0.30 +/- 0.13 ng/mL; P < 0.001), FAI (P < 0.001) and low SHBG (P = 0.004) compared to controls. TT/DHT ratio was significantly higher in PCOS with impaired glucose tolerance (IGT) (P = 0.037) and metabolic syndrome (MetS) (P = 0.041). The best cutoff value for TT/DHT ratio to diagnose PCOS was observed to be 2.38 (sensitivity: 70%, specificity: 32.5% and area under the curve (AUC): 0.753). TT/DHT ratio also showed positive correlation with weight (r = 0.323, P = 0.042), waist circumference (WC) (r = 0.372, P = 0.018), HOMA-IR (r = 0.385, P = 0.014), 2-h post 75-g glucose (2h-PG), (r = 0.413, P = 0.008) and triglyceride (TG) level (r = 0.402, P = 0.010) in PCOS. Conclusions: There is a close relation between the TT/DHT ratio and adverse metabolic outcome in PCOS. Therefore, TT/DHT ratio may be considered as a predictor of adverse metabolic findings in PCOS.