Suppression of Testosterone and Androstenedione Production Rates with Dexamethasone in Women with Idiopathic Hirsutism and Polycystic Ovaries

Testosterone and androstenedione plasma levels were measured in 7 normal women and 22 hirsute women with either idiopathic hirsutism (IH) or polycystic ovaries (PCO). During dexamethasone administration, plasma testosterone decreased 25% in normal subjects and 40–50% in the patients with IH and PCO. Plasma androstenedione levels were suppressed 40–55% in the normal and hirsute women. The mean testosterone metabolic clearance rate for 8 hirsute women increased 10 % during dexamethasone administration but there was no significant change in the androstpnedione metabolic clearance. Thus, the decrease in blood androgen levels produced by glucocorticoid was a consequence of decreased androgen production. These studies indicate further that a gland which is suppressed by dexamethasone is responsible for a significant fraction of the excess androgen production in women with either IH or PCO.