Heterogeneous results of serum testosterone obtained in multiple blood samples from women with idiopathic hirsutism in both basal and post-dexamethasone conditions.

Serum radioimmunoassayable testosterone (T), cortisol and luteinizing hormone (LH) were determined before and after dexamethasone (DXM) administration in 35 patients with idiopathic hirsutism (IH). Blood samples were taken at 15-min intervals during 1 hour in both basal and post-DXM conditions. Testosterone values obtained in 5 normal women in the same conditions during the early follicular phase were (mean +/- SD): baseline, 2.26 +/- 0.49 nmol/l; post-DXM, 0.80 +/- 0.35 nmol/l. Serum T levels in the whole group of patients with IH were significantly higher than those in the control group (mean +/- SD): baseline, 3.30 +/- 1.80nmol/l; post-DXM, 1.67 +/- 1.49nmol/l. Patients with IH were divided into 4 groups according to T results in the DXM test (mean +/- SD in both basal and post-DXM conditions, respectively): group 1 (n = 13) 1.67 +/- 0.66 and 0.62 +/- 0.35nmol/l; group 2 (n = 11) 3.89 +/- 1.63 and 3.09 +/- 1.49nmol/l; group 3 (n = 6) 3.96 +/- 1.46 and 0.87 +/- 0.73nmol/l; and group 4 (n = 5) 5.45 +/- 1.25 and 2.05 +/- 0.38nmol/l. In all cases, maximal adrenal inhibition, as judged by serum cortisol, was obtained. No LH modifications after DXM were obtained in any of the cases. Our results demonstrate that there is no common androgenic abnormality in IH. It is possible to obtain normal or high circulating T levels. The findings of this study also suggest that the adrenals, to ovary or both may be the sources of high T levels.