Comparison of the overnight metyrapone and glucagon stimulation tests in the assessment of secondary hypoadrenalism. (10th April 2013)

• Record Type: Journal Article
• Authors: Cegla, Jaimini; Jones, Ben; Seyani, Lata; Papadoulou, Deborah; Wynne, Katie; Martin, Niamh M.; Meeran, Karim; Chapman, Richard; Donaldson, Mandy; Goldstone, Anthony P.; Tan, Tricia
• Is Part Of: Clinical endocrinology. Volume 78:Number 5(2013:May)
• Page Start: 738
• Page End: 742
• Publication Date: 2013-04-10
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.12043
• Languages: English
• ISSNs: 0300-0664

Abstract

<abstract abstract-type="main" id="cen12043-abs-0001"> <title>Summary</title> <sec id="cen12043-sec-0001" sec-type="section"> <title>Objective</title> <p>The insulin tolerance test (ITT) is contraindicated in a proportion of patients with suspected ACTH deficiency. The aim of this study was to investigate the diagnostic accuracy of the glucagon stress test (GST) compared with the overnight metyrapone test (OMT) in patients with contraindications to ITT.</p> </sec> <sec id="cen12043-sec-0002" sec-type="section"> <title>Design</title> <p>This was a prospective comparison of the GST to the OMT in patients with suspected ACTH deficiency and contraindications to the ITT. The OMT was used as the standard for comparison. The study was conducted at two tertiary referral centres for pituitary disease.</p> </sec> <sec id="cen12043-sec-0003" sec-type="section"> <title>Patients</title> <p>Seventy‐eight patients underwent contemporaneous OMT and GST of whom 61 had sufficient suppression of cortisol during the OMT to be included in the comparison. Forty had suffered traumatic brain injury, 36 had organic pituitary disorders and two were classified as 'other'.</p> </sec> <sec id="cen12043-sec-0004" sec-type="section"> <title>Measurements</title> <p>ACTH sufficiency was defined as 0800h 11‐deoxycortisol ≥ 200 nmol/l on OMT and peak cortisol ≥ 440 nmol/l on GST, as per local reference ranges.</p> </sec> <sec id="cen12043-sec-0005" sec-type="section"> <title>Results</title> <p>There was significant discrepancy between the proportion of patients diagnosed with ACTH deficiency using the OMT (39%) and GST (89%). From our data, a GST peak cortisol cut‐off of ≥350 n<sc>m</sc> provides the combination of optimal sensitivity (71%) and specificity (57%), compared with a higher sensitivity (88%) but poor specificity (11%) using a cut‐off of ≥440 n<sc>m</sc>.</p> </sec> <sec id="cen12043-sec-0006" sec-type="section"> <title>Conclusions</title> <p>The GST should be used with caution as a diagnostic test of ACTH reserve. The OMT should be used in preference to the GST to assess the hypothalamic pituitary adrenal axis where ITT is contraindicated.</p> </sec> </abstract>