Diagnostic utility of the glucagon stimulation test in comparison to the insulin tolerance test in patients following pituitary surgery
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Diagnostic utility of the glucagon stimulation test in comparison to the insulin tolerance test in patients following pituitary surgery. / Berg, Christian; Meinel, Timo; Lahner, Harald; Yuece, Ali; Mann, Klaus; Petersenn, Stephan.
In: European Journal of Endocrinology, Vol. 162, No. 3, 2009, p. 477-82.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Diagnostic utility of the glucagon stimulation test in comparison to the insulin tolerance test in patients following pituitary surgery
AU - Berg, Christian
AU - Meinel, Timo
AU - Lahner, Harald
AU - Yuece, Ali
AU - Mann, Klaus
AU - Petersenn, Stephan
N1 - Keywords: Adenoma; Adrenal Insufficiency; Adult; Analysis of Variance; Blood Glucose; Chemiluminescent Measurements; Craniopharyngioma; Female; Glucagon; Human Growth Hormone; Humans; Hydrocortisone; Hypopituitarism; Hypothalamo-Hypophyseal System; Insulin; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Neurosurgical Procedures; Pituitary Gland; Pituitary Neoplasms; Pituitary-Adrenal System; Prospective Studies; ROC Curve; Sensitivity and Specificity; Statistics, Nonparametric; Time Factors
PY - 2009
Y1 - 2009
N2 - OBJECTIVE: The 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 PATIENTS: ITT 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. RESULTS: In 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. CONCLUSION: In 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.
AB - OBJECTIVE: The 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 PATIENTS: ITT 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. RESULTS: In 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. CONCLUSION: In 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.
U2 - 10.1530/EJE-09-0824
DO - 10.1530/EJE-09-0824
M3 - Journal article
C2 - 19996199
VL - 162
SP - 477
EP - 482
JO - European Journal of Endocrinology
JF - European Journal of Endocrinology
SN - 0804-4643
IS - 3
ER -
ID: 18698084