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my personal edition > pituitary > news
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DGDispatch
Evaluation of Serum Test to Screen for Secondary Adrenal Insufficiency: Presented at AACE
By Maggie Schwarz
WASHINGTON, DC -- May 27, 2005 -- A 25 mcg cosyntropin stimulation test is both accurate and convenient for evaluating the hypothalamic-pituitary-adrenal (HPA) axis, according to new research.
"We've been using a screening test for secondary adrenal insufficiency that's more accurate than traditional tests," said Ali Usmani, MD, a third-year resident in internal medicine at the Cleveland Clinic Health System in Cleveland, Ohio, United States.
Dr. Usmani said he and his associates were seeking a good screening test because the 1 and 250 mcg cosyntropin stimulation tests are unreliable. They've been using a 25 mcg test for 2 years, evaluated it, and announced its level of diagnostic accuracy here May 19th at the American Association of Clinical Endocrinologists (AACE) 14th Annual Meeting and Clinical Congress.
In their study, 43 patients underwent the cosyntropin stimulation test and either an insulin tolerance test (n = 26) or metyrapone test (n = 17). Twenty controls underwent measurement of their serum cortisol level before and at 30 and 60 minutes after administration of cosyntropin.
In patients who underwent a pituitary surgical procedure, all tests were performed at least 4 weeks postoperatively. Most (31 of 43) of the patients had a pituitary macroadenoma. Magnetic resonance imaging of the pituitary showed normal findings in 14 patients and a microadenoma in six.
A cortisol cutoff value of 18.0 mcg/dL at 30 minutes resulted in the best combination of sensitivity and specificity, at 88.9% and 59.5%, respectively. Of the 27 patients who failed the insulin tolerance test or metapyrone test, three passed the 25 mcg cosyntropin stimulation test. Two of these three patients did not benefit from glucocorticoid therapy, which was subsequently discontinued without sequelae.
"Though the specificity of 59.5% isn't that impressive, it's acceptable for a screening test," explained Dr. Usmani. "If the test comes out negative, there's an 88.9% chance the patient does not have secondary adrenal insufficiency. If the test comes out positive, the patient is then referred for insulin tolerance testing or the metapyrone test, if the patient is not a candidate for insulin tolerance testing."
Secondary adrenal insufficiency is a result of pituitary dysfunction. "It's an important diagnosis to catch," said Dr. Usmani, "since it can be the cause of malaise, fatigue, weight problems, and depression. Secondary adrenal insufficiency can be fatal in cases of stress, shock, or surgery because the body doesn't produce enough adrenal hormone."
[Presentation title: Hypothalamic-Pituitary-Adrenal Axis Testing With Use of a 25-mcg Cosyntropin Stimulation Test. AACE: 896.]
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