Effect of Estrogen Administration on Androgen Production and Plasma Luteinizing Hormone in Hirsute Women1

Abstract

Large doses of estrogens were given for 10–200 days to 11 hirsute women in an attempt to suppress LH production, and thus androgen production originating from the ovaries. In only 2 of 7 patients did estrogen result in suppression of plasma LH. In the remaining 5 women, LH levels were unchanged, and abnormalities of androgen production persisted. Estrogen treatment was noted to decrease the metabolic clearance rates of testosterone (MCR_T) in all 11 patients independent of its effect on testosterone production rate . AS a result, plasma T remained unchanged, increased or decreased, and was an unreliable parameter of the effect of estrogen on testosterone production. No consistent change was noted in MCR of androstenedione (MCR_Δ) after estrogen treatment. These studies demonstrate that estrogen administration 1) does not suppress LH in the majority of hirsute women, and 2) alters the peripheral metabolism of testosterone such that measurement of plasma T can lead to erroneous conclusions. The use, therefore, of estrogen suppression tests in the evaluation of hirsute women must be interpreted with caution.