THE INFLUENCE OF THE THYROID ON ADRENAL CORTICAL FUNCTION

Abstract

Plasma cortisol levels were normal in most patients with myxedema or thyrotoxicosis. Urine 17-ketosteroids were low in both myxedema and thyrotoxicosis. Urine corticoids were low in myxedema, and normal or moderately elevated in thyrotoxicosis. Urine corticoids returned to normal more promptly than the 17-ketosteroids following treatment of the thyroid disorder. Infused steroids disappeared from the plasma at an increased rate in thyrotoxicosis, and at a decreased rate in myxedema. Appropriate therapy for thyroid disease returned metabolism of infused steroids to normal. Rate of synthesis of cortisol was reduced in myxedema and increased in thyrotoxicosis, and these alterations in rate of secretion of cortisol were not associated with a significant change in size of the miscible pool. Institution of the euthyroid state in these patients returned adrenal cortisol production to normal.