Work

A case of low cortisol-binding globulin: use of plasma free cortisol in interpretation of hypothalamic-pituitary-adrenal axis tests

Year: 2006

Type: article

Abstract: We investigated a patient with suspected hypopituitarism who showed subnormal cortisol responses to stimulation tests with adrenocorticotrophic hormone (ACTH) and hypoglycaemia, but normal ACTH and 11-deoxycortisol responses in the metyrapone test. Cortisol-binding globulin (CBG) was measured by enzyme-linked immunosorbent assay (ELISA), and was used to calculate plasma free cortisol and free cortisol index. The patient had a low plasma CBG concentration. Reinterpreted in terms of free cortisol and free cortisol index, his responses to ACTH were normal. We conclude that despite subnormal total cortisol responses to ACTH and hypoglycaemia, the patient had a normal hypothalamic-pituitary-adrenal (HPA) axis. Measurement of CBG concentration and calculation of free cortisol or free cortisol index can help avoid false interpretations of dynamic tests of the HPA axis based on plasma total cortisol.

Source: Annals of Clinical Biochemistry International Journal of Laboratory Medicine

DOI: 10.1258/000456306776865241

Authors: James S Davidson, Mark J Bolland, Michael S Croxson, Weldon Chiu, John G Lewis

Institutions: Auckland City Hospital, Canterbury Health Laboratories

Language: English

Topic: Adrenal Hormones and Disorders

Subfield: Endocrinology, Diabetes and Metabolism

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: bronze

OpenAlex ID: W2005446354

FWCI: 1.357

Cites: 10

Cited by: 19

Related to: 10