Serum androgen levels in hyperthyroid women

Thyroid hormone is known to affect androgen metabolism, however, there are few studies in which alterations of androgen metabolism are simultaneously examined in patients with clinical thyroid disorders. In this study, we investigated the alterations of thyroid hormone and androgens before and during treatment in patients with hyperthyroidism. Fifteen female patients with hyperthyroidism due to Graves' disease were studied. From these patients, blood samples were obtained before treatment and at 1 month (M), 2M, 3M, 4M and 6M after beginning of treatment. Concentrations of free T4(FT4), free T3(FT3), testosterone (T), androstenedione (delta 4A), dihydrotestosterone (DHT), 5 alpha-androstane-3 alpha, 17 beta-diol(3 alpha-diol) and androsterone (AD) and sex hormone binding globulin (SHBG) were measured by radioimmunoassays (RIAs) or immunoradiometric assay (IRMA). As normal controls, ten healthy women were also studied. Before treatment concentrations of DHT (mean +/- SD: 3.35 +/- 0.78 nmol/L), 3 alpha-diol (0.78 +/- 0.11 nmol/L), AD (6.73 +/- 0.64 nmol/L) and SHBG (184.9 +/- 68.1 nmol/L) were significantly elevated compared with those of normal controls. T and delta 4A levels were not significantly different from normal values. DHT/T ratio indicating 5 alpha-reductase activity was 4.62 +/- 2.55 and significantly higher than that in normal controls. At 2 months after beginning of treatment with anti-thyroid drugs, thyroid function (FT4 and FT3) became normal and at 3 months after beginning of treatment, DHT, 3 alpha-diol, AD and DHT/T ratio decreased to normal range. SHBG level was gradually decreased, however still higher than that of the normal control group at 6 months after beginning of treatment. There was a time lag in recovery between serum androgen levels and SHBG level.