3 alpha, 17 beta-androstanediol glucuronide in plasma. A marker of androgen action in idiopathic hirsutism.

Biologically active androgens and peripheral androgen metabolites in plasma were measured in 25 women with idiopathic hirsutism (IH). Plasma testosterone was not significantly elevated. Free testosterone however was increased although the elevation was not impressive (10.9 +/- 6.6 SD vs. 3.3 +/- 1.5 ng/dl) and one-fourth of the cases had normal unbound testosterone. Dihydrotestosterone (DHT) values were elevated (23.5 +/- 14 vs. 12.5 +/- 3.59) but again over half of the values were within the normal range. In our series of mild to moderate cases, 3 alpha-diol was not at all discriminatory. However, plasma 3 alpha-diol glucuronide was markedly increased (604 +/- 376 vs. 40 +/- 10 ng/dl), and elevated in all but one mild case. Previous studies document that DHT is the important androgen in skin and formation of DHT and 3 alpha-diol is markedly increased in vitro in IH. Since 3 alpha-diol glucuronide is derived largely from extrasplanchnic events, beta-glucuronidase is present in skin, and androgen stimulates formation of the enzyme in extrasplanchnic tissue, we conclude that 3 alpha-diol glucuronide is a marker of peripheral androgen action and markedly elevated in IH.