CYP17A1 and polycystic ovary syndrome: Furthermore, hyperglycemia or glucose intolerance may indirectly suppress the synthesis of hepatic sex hormone-binding globulin synthesis (SHBG), leading to increased serum levels of unbound steroid hormones which in turn modulate the activity of the key regulatory enzyme of androgen biosynthesis, P450c17, in the ovarian theca interna and interstitial cells resulting in elevated androgen levels in PCOS women.