Endocrine Abstracts

A systematic survey of low S-cortisol levels at the department of clinical chemistry: indications for testing and frequency of undiagnosed adrenal insufficiency.

Background: S-cortisol is frequently analyzed at clinical chemistry departments. Low levels of S-cortisol needs to be promptly acted on if the cause is undiagnosed adrenal insufficiency (AI). The causes of S-cortisol testing are however multiple and low levels are necessarily not alarming if found in patients already under clinical evaluation or surveillance. Consequently, far from all clinical chemistry departments have as routine to alert clinicians on low S-Cortisol, potentially delaying AI diagnosis.

Aim: To identify individuals with S-cortisol < 150 nmol/l and determine the indication for testing and the number of cases of undiagnosed AI.

Material and methods: We retrospectively went through the results from all S-Cortisol analyses performed at the Clinical chemistry department at the Karolinska university hospital during six months, January 1 until June 30 2013. Individuals with S-cortisol <150 nmol/l were identified and their medical records were reviewed to determine the indication for S-cortisol testing.

Results: 993 S-cortisol analyses <150 nmol/l were identified. Medical records were available from 866 individuals (female 539, children 94). The most common indication for the S-cortisol testing was dexamethasone inhibition test n 334, followed by monitoring of pituitary insufficiency n 62. In 146 patients the indication for testing was unclear and not stated in the records. In 2% (n 19) of the patients previously undiagnosed AI was identified. Many patients were severely ill at the time of testing, 78 (9%) later deceased from other causes than AI, but in one case, undiagnosed Addison’s disease.

Conclusion: S-cortisol is frequently analyzed and the most common cause of testing is evaluation or surveillance of patients already carefully cared for. A handful of patients however suffer from undiagnosed AI. If establishing a routine to alert clinicians on low S-cortisol levels, indication for the analysis should be marked in ordered to avoid unnecessary concern.