Differential studies on the mechanism of serum androgen and androgen-binding abnormalities in hirsutism

Twenty-eight patients with hirsutism were studied. Elevated levels of testosterone and dihydrotestosterone (T + DHT) and a decreased dihydrotestosterone precipitation index (DHT-PI) were found in about half the patients studied. The DHT-PI is a sensitive measure of steroid-binding β-globulin (SBβG). The DHT-PI was much more abnormal in patients with oligomenorrhea than in those with regular menses despite similar T + DHT levels. Chronic suppression of T + DHT levels with prednisone in hirsute patients did not normalize the DHT-PI. The addition of Premarin resulted in normalization of the DHT-PI. These findings would favor the hypothesis that the serum androgen-binding protein abnormality in hirsute females is not maintained by significantly increased circulating androgen levels.