A Significant Adverse Correlation between Serum Cortisol and TSH in a Case of Cyclic Cushing's Disease Based on a Continuous Three-year Observation

• Published in: ENDOCRINE JOURNAL Vol. 50; no. 6; pp. 833 - 834
• Main Authors: Yamaguchi, Kohei, Hashiguchi, Yasuhiro
• Format: Journal Article
• Language: English
• Published: Japan The Japan Endocrine Society 2003
• Subjects: Aged; Cushing Syndrome - blood; Female; Humans; Hydrocortisone - blood; Periodicity; Thyrotropin - blood
• ISSN: 0918-8959; 1348-4540
• DOI: 10.1507/endocrj.50.833

The suppressive effects of exogeneous glucocorticoid on the hypothalamo-pituitary-thyroid axis is a well-known fact [1-3]. There have also been many studies of healthy volunteers [1], patients with Cushing's syndrome [4] and patients with congenital adrenal hyperplasia [5], regarding the role of endogenous glucocorticoid in the regulation of TSH. However, there have been no reports on the relationship of serum cortisol and TSH in cyclic Cushing's syndrome. A 71-year-old woman with clinical signs of Gushing's disease was observed continuously for three years during which serum cortisol levels fluctuated from 10 to 57 μg/dl and serum TSH levels ranged 0.05 to 3.15 μIU/ml. As can be seen in the main Fig.1, cortisol levels peaked twice during the first two years. Beginning in May 1997 the patient began receiving 120-180 mg/day of trilostane, and seemed to respond. However, in July 1998, her serum cortisol levels began to rise to about 20 μg/dl (this period is not shown in the main Fig.1). The patient demonstrated two important features of cyclic Gushing's disease：absence of ACTH response to CRH administration and non-suppressibility in response to high dose dexamethasone other than the cyclicity of ACTH and cortisol.