This worsens the underlying androgen excess and insulin resistance and inhibits the response to treatment, and is an indication for appropiate advice on diet and exercise. In severe cases the insulin resistance may have a visible manifestation as acanthosis nigricans on the neck and in the axillae. SHBG can be measured in some centres. Other androgens . Androstenedione and DHEA sulphate are frequently elevated in PCOS, and even more elevated in congenital adrenal hyperplasia and virilizing tumours.
Levels are variable in other causes.
The most consistent investigation in PCOS is ovarian ultrasound, although a skilled observer is necessary. The typical ultrasonic features are those of a thickened capsule, multiple 3-5mm cysts and hyperechogenic stroma. It should also be noted that prolonged hyperandrogenization from any cause may lead to polycystic changes in the ovary. Ultrasound may also reveal virilization ovarian tumours, although these are often small. Mild hyperprolactinaemia is common in PCOS but rarely exceeds 1500mUL-1.