Recovery of pituitary function in the late-postoperative phase after pituitary surgery: results of dynamic testing in patients with pituitary disease by insulin tolerance test 3 and 12 months after surgery

The insulin tolerance test (ITT) is considered the gold standard for assessment of GH and ACTH reserve in patients with pituitary disease following pituitary surgery and is usually performed after 6–12 weeks. However, abnormal axes may not be completely recovered by then. The aim of this study was to evaluate dynamic testing 3 and 12 months after transsphenoidal pituitary surgery.Design and patientsSerial dynamic testing was performed in 36 patients (13 women, age 18–78) at 3 and 12 months after transsphenoidal surgery.ResultsCompared with 3-month results, median GH peak levels during ITT after 12 months increased by 38% (P<0.05). In patients initially classified as GH deficiency (GHD), median GH peak increased after 12 months by 23% (P<0.05). At 3 and 12 months, 36% (13/36) and 47% (17/36) were GH sufficient respectively. Median cortisol peak levels after 12 months increased by 17% (P<0.01) compared with 3-month ITT. In ACTH-insufficient (AI) patients, peak cortisol levels increased significantly by 12% (P<0.05) at 12 months, and in ACTH-sufficient patients, peak cortisol levels increased significantly by 13% (P<0.05). At 12 months, there was recovery from AI in 11% of the patients, and recovery from GHD in 11% of patients.ConclusionsSerial dynamic testing results in a change in classification by ITT results in a relevant proportion of patients. Dynamic testing should be repeated during follow-up.

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Prospective comparison of the glucagon stimulation test (GST) with the insulin tolerance test (ITT) in patients following pituitary surgery

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/s-0028-1096360 ◽

2008 ◽

Vol 116 (09) ◽

Author(s):

C Berg ◽

T Meinel ◽

A Yüce ◽

H Lahner ◽

K Mann ◽

...

Keyword(s):

Pituitary Surgery ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Stimulation Test ◽

Glucagon Stimulation Test ◽

Insulin Tolerance ◽

Prospective Comparison

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Comparison of the Low Dose Short Synacthen Test (1 μg), the Conventional Dose Short Synacthen Test (250 μg), and the Insulin Tolerance Test for Assessment of the Hypothalamo-Pituitary-Adrenal Axis in Patients with Pituitary Disease

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jcem.84.3.5535 ◽

1999 ◽

Vol 84 (3) ◽

pp. 838-843 ◽

Cited By ~ 2

Author(s):

T. A. M. Abdu ◽

T. A. Elhadd ◽

R. Neary ◽

R. N. Clayton

Keyword(s):

Low Dose ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Adrenal Axis ◽

Conventional Dose ◽

Pituitary Disease ◽

Insulin Tolerance ◽

Synacthen Test ◽

Short Synacthen Test ◽

Pituitary Adrenal Axis

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Diagnostic utility of the glucagon stimulation test in comparison to the insulin tolerance test in patients following pituitary surgery

Acta Endocrinologica ◽

10.1530/eje-09-0824 ◽

2010 ◽

Vol 162 (3) ◽

pp. 477-482 ◽

Cited By ~ 55

Author(s):

Christian Berg ◽

Timo Meinel ◽

Harald Lahner ◽

Ali Yuece ◽

Klaus Mann ◽

...

Keyword(s):

Roc Analysis ◽

Pituitary Surgery ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Stimulation Test ◽

Diagnostic Utility ◽

Glucagon Stimulation Test ◽

Gh Secretion ◽

Insulin Tolerance ◽

Potential Alternative

ObjectiveThe glucagon stimulation test (GST) like the insulin tolerance test (ITT) stimulates both ACTH and GH secretion. However, there are limited data with modern assays on sensitivity and specificity for GST in comparison to ITT. The aim of this study was to evaluate the diagnostic utility of the GST for GH deficiency (GHD) and adrenal insufficiency (AI) in patients following pituitary surgery.Design and patientsITT and GST were performed within 7 days in 49 patients at least 3 months after transsphenoidal surgery. Serum GH and cortisol were measured by Immulite 2000 assay (Siemens AG). Receiver-operating characteristic (ROC) analysis was performed to identify the thresholds for GST.ResultsIn ITT, 18/49 cases were classified as AI. ROC analysis revealed a peak cortisol value >599 nmol/l in GST for adrenal sufficiency with 100% specificity and 32% sensitivity, and a peak cortisol <277 nmol/l with >95% specificity and 72% sensitivity for AI. Of the 49 subjects, 25 (51%) demonstrated levels between these cut-offs and could not be diagnosed by GST alone with sufficient accuracy. Regarding GHD, 21/49 cases were classified as insufficient by ITT. ROC analysis revealed a cut-off of 2.5 ng/ml with 95% sensitivity and 79% specificity. Of the 49 cases, seven (14%) were discordant in terms of defining GHD, with six subjects being treated for GHD according to GST although being sufficient in ITT.ConclusionIn our prospective series of patients with pituitary disease, GST is a potential alternative test for the assessment of GH reserve, but is a poor test for ACTH reserve. Test-specific cut-offs should be applied to avoid misinterpretation.

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