THYROID-ANDROGEN INTERRELATIONS AND THE HYPOCHOLESTEREMIC EFFECT OF ANDROSTERONE*

Abstract

Myxedema is associated with a profound change in the metabolism of androgen. Endogenous production of androsterone was very low in 6 myxedematous patients, and a much smaller fraction of exogenous testosterone-4-C14 was converted to androsterone than in euthyroid subjects. In 1 hyperthyroid patient studied the reverse was observed, in that endogenous androsterone production was elevated. Administration of triiodothyronine to myxedematous patients altered this defect in metabolism and restored an essentially normal metabolic pattern for both endogenous and exogenous androgen. Administration of triiodothyronine to euthyroid subjects produced a similar change in endogenous and exogenous androgen metabolism, in that androsterone production was materially increased. From these results the hypothesis was made that some of the peripheral manifestations of excess or deficit of thyroid hormone might be mediated by the metabolites of steroid androgens. In confirmation, it was found that androsterone caused a significant decrease of the serum cholesterol level in myxedematous patients, in subjects with hypercholesterolemia of varied origin, and in normocholesteremic subjects. One myxedematous patient showed an increase in basal oxygen consumption during treatment with androsterone.