Salivary Testosterone: A Good Measure to Reflect Free Testosterone

Abstract

To the Editor. —Salivary testosterone— sampling regimens have the advantage of frequent, easy collection by a noninvasive stress-free technique, and its measurement can provide an index of free testosterone in plasma or serum. 1-3 Several situations, such as hirsutism, pregnancy, and hyperthyroidism, are known in which there is a discordance between total testosterone levels in serum and clinical signs of androgenicity. 3,4 Thus, in Graves' disease testosterone binding is generally increased by thyroid hormone levels and, therefore, levels for total testosterone are increased, whereas levels for free testosterone are normal. 5 We measured total serum and salivary testosterone with a radioimmunoassay kit (Farmos Diagnostica, Oulu, Finland) in a group of 59 normal women and 25 women with Graves' disease and who did not undergo treatment (age, 20 to 56 years). Our data show that the normal levels for total testosterone in serum were 53 ±21 ng/dL and 2.9±1 ng/dL