Hyperthyroidism and Cortisol Secretion in Man

Abstract

The pattern of cortisol secretory activity of four patients with severe spontaneous hyperthyroidism were studied by sampling plasma every 20 min around the 24 hr clock and measurement of cortisol by competitive protein binding. Estimates of cortisol secretion rate were made employing the equation of Hellman, Nakada, Curti, Weitzman, Kream, Roffwarg, Ellman, Fukushima and Gallagher (J Clin Endocrinol Metab 30: 411, 1970). In addition, the secretion rate in certain patients was measured by the rinary metabolite(s) method. It was demonstrated that: 1) there were more cortisol secretory episodes than normal; 2) more of the 24-hr day was spent in adrenal secretory activity; 3) there was increased production of cortisol in conjunction with a very much shortened half-life of plasma cortisol; 4) there was an almost certain increased functional adrenal capacity to nearly double normal as evident from greater cortisol production per unit time; and 5) there was retention of the normal post-midnight concentration of ...