Plasma ACTH level in patients with thyrotoxicosis before and after treatment

This paper deals with the measurements of plasma ACTH and serum cortisol before and after a 4—5 week treatment with antithyroid drugs in 62 cases with thyrotoxicosis. It was found that before treatment the plasma ACTH concentration was elevated and the serum cortisol was lowered. After treatment, the ACTH level declined, maximally in patients who became euthyroidism. And the cortisol level rose, but was still lower than that in normal subjects. This results suggest that thyroid hormone accelerates the turnover of cortisol and causes decrease of serum cortisol. In feedback, the secretion of ACTH was increased for maintaining an adequate level of serum cortisol.
Half of these patients showed an elevation of 2-hour postprandial blood sugar, which was not relevant to the fluctuation of cortisol level. It was believed that excessive increase of thyroid hormone may give rise to impaired glucose tolerance.