Mini-review of hair cortisol concentration for evaluation of Cushing syndrome

ABSTRACT

Introduction: The diagnosis of endogenous Cushing syndrome is often challenging and requires multiple repeated blood, urine, and saliva tests to detect elevated cortisol levels. Hair cortisol concentration has been described as a marker of long-term exposure to systemic cortisol in patients with Cushing syndrome. Like hemoglobin A1c is used to detect serum glucose exposure over months, segmental hair cortisol can help identify patients with milder forms of and/or periodic or cyclical Cushing syndrome, which may reduce time and costs associated with collection of urine, salivary, and serum cortisol.

Areas covered: Success of hair cortisol in detection of Cushing syndrome will be discussed in context of current literature, including differences between total or segmental hair cortisol in accurately determining timeline of cortisol exposure. Optimal methods of hair collection, storage, processing, and analysis and efforts toward standardization will be a major focus.

Expert commentary: Recent evidence suggests increased sensitivity and specificity of hair cortisol in detecting Cushing syndrome. Future guidelines should consider this test as a routine part of the repertoire of screening tests for Cushing syndrome. Possible confounders to explain discrepant results in the literature will be discussed.

KEYWORDS:

• Hair
• cortisol
• hair cortisol
• Cushing syndrome
• Cushing disease
• hypercortisolemia

Acknowledgments

We thank Nichole Jonas and Jeremy Swam for assistance in creating and editing images for this manuscript. We thank Diane Cooper, MSLS, NIH Library, for assistance in writing this manuscript.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This research was supported by the Intramural Research Program of Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), clinical trials [NCT00005927] (Clinical and Molecular Analysis of ACTH Independent Steroid Hormone Production in Adrenocortical Tissue) and [NCT00001595] (A Clinical and Genetic Investigation of Pituitary Tumors and Related Hypothalamic Disorders), NIH grants: 1ZIAHD008920-06, 1ZIJHD008867-09, 1ZIJHD008867-08.