Peak cortisol response to insulin tolerance test: how reproducible is it really?

The short Synacthen (tetracosactrin) test (SST) is an established method of assessing adrenocortical reserve, and is increasingly replacing the insulin tolerance test (ITT) for the assessment of the hypothalamic-pituitary-adrenal (HPA) axis. However, there is no consensus on how the test is performed, and various time points and routes of administration are used. The present study was done, first, to determine whether there was any difference in cortisol responses when Synacthen was administered intramuscularly compared with intravenously and, secondly, to compare cortisol responses at 30 and 60 min. We found no significant difference between the two routes of administration. However, cortisol responses at 60 min were significantly higher than at 30 min ( P < 0·05). Previous validations for the use of the SST in place of the ITT have used cortisol responses 30 min after Synacthen. We conclude that where the SST is used to assess the HPA axis, cortisol response at 30 min after intravenous Synacthen should be used.

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Intravenous insulin tolerance test: criteria for evaluation of the growth hormone and cortisol response

Acta Endocrinologica ◽

10.1530/acta.0.107s0031 ◽

1984 ◽

Vol 104 (4_Supplc) ◽

pp. S31-S33

Author(s):

M. C. Alevizaki - Harhalaki ◽

C. C. Alevizaki ◽

H. D. Demertzi ◽

D. G. Ikkos ◽

A. Papas

Keyword(s):

Growth Hormone ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Cortisol Response ◽

Intravenous Insulin ◽

Insulin Tolerance ◽

Test Criteria ◽

Criteria For Evaluation

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MORNING SERUM CORTISOL LEVEL PREDICTS CENTRAL ADRENAL INSUFFICIENCY DIAGNOSED BY INSULIN TOLERANCE TEST

Neuroendocrinology ◽

10.1159/000514216 ◽

2021 ◽

Author(s):

Valentina Gasco ◽

Chiara Bima ◽

Alice Geranzani ◽

Jacopo Giannelli ◽

Lorenzo Marinelli ◽

...

Keyword(s):

Adrenal Insufficiency ◽

Serum Cortisol ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Cortisol Concentration ◽

Serum Cortisol Level ◽

Cortisol Response ◽

Insulin Tolerance ◽

Morning Serum Cortisol ◽

Serum Cortisol Concentration

Introduction According to guidelines, a morning serum cortisol level <83 nmol/L is diagnostic for central adrenal insufficiency (CAI), a value >414 nmol/L excludes CAI, while values between 83 and 414 nmol/L require stimulation tests. However, there are no currently reliable data on morning serum cortisol for prediction of cortisol response to insulin tolerance test (ITT). Objective Using the receiver operating characteristic curve analysis, the purpose of this study was to detect the morning serum cortisol cut-off with a specificity (SP) or a sensitivity (SE) above 95% that identify those patients who should not be tested with ITT. Methods We included 141 adult patients (83 males) aged 42.7+/-12.3 (mean +/- SD) years old. Based on serum cortisol response to ITT, patients have been divided in two groups: subjects with CAI (peak serum cortisol <500 nmol/L; 65 patients) and subjects with preserved adrenocortical function (peak cortisol >500 nmol/L; 76 patients). Results The best morning cortisol cut-off, in terms of SE (87.7%) and SP (46.1%), was ≤323.3 nmol/L. The cut-off of morning serum cortisol concentration that best predicted a deficient response to ITT was ≤126.4 nmol/L (SE 13.8%, SP 98.7%). The cut-off of morning serum cortisol concentration that best predicted a normal response to ITT was >444.7 nmol/L (SE 96.9%, SP 14.5%). Conclusions This is the first study that identifies a morning serum cortisol cut-off that best predict the response to ITT in order to simplify the diagnostic process in patients with suspected CAI. A new diagnostic flow chart for CAI is proposed.

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THE INSULIN TOLERANCE TEST AFTER PRE-TREATMENT WITH DEXAMETHASONE

Acta Endocrinologica ◽

10.1530/acta.0.0830341 ◽

1976 ◽

Vol 83 (2) ◽

pp. 341-356 ◽

Cited By ~ 11

Author(s):

P. O. Osterman ◽

L. Wide

Keyword(s):

Plasma Cortisol ◽

Tolerance Test ◽

Plasma Cortisol Level ◽

Insulin Tolerance Test ◽

Cortisol Response ◽

Insulin Tolerance ◽

Basal Plasma ◽

Pre Treatment ◽

Serum Gh ◽

Dexamethasone Suppression

ABSTRACT The plasma 11-hydroxycorticosteroid and serum GH responses to insulin-induced hypoglycaemia were studied in 25 healthy volunteers. The results of a control insulin tolerance test were compared with those of 2 similar tests which were performed after pre-treatment with dexamethasone 0.5 and 1.0 mg, respectively. The GH response to hypoglycaemia was significantly lower in women than in men in all 3 tests. In men, but not in women, the GH response was lower after pre-treatment with 1 mg dexamethasone than in the other 2 tests. The plasma 11-hydroxycorticosteroid response was significantly greater after pre-treatment with 0.5 mg dexamethasone than in the control test, and was at least as good after 1 mg dexamethasone. After pre-treatment with dexamethasone the subjects experienced less discomfort and a shorter duration of sweating than in the control insulin tolerance test. Pre-treatment with 1 mg dexamethasone also has other advantages. Thus, the basal plasma cortisol level is low and stable, which facilitates estimation of the magnitude of the cortisol response. Furthermore, information is obtained about the dexamethasone suppression response.

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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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Influence of insulin-induced hypoglycemia on the hemostatic and fibrinolytic system in patients with hypothalamicpituitary disorders

Hämostaseologie ◽

10.1055/s-0038-1655335 ◽

1998 ◽

Vol 18 (02) ◽

pp. 74-79

Author(s):

K.-H. Zurborn ◽

H. D. Bruhn ◽

H. Mönig

Keyword(s):

Factor Viii ◽

Plasminogen Activator ◽

Tolerance Test ◽

Insulin Tolerance Test ◽

Fibrinolytic System ◽

Tissue Type ◽

Insulin Tolerance ◽

Factor Viii Antigen ◽

Pai 1 ◽

D Dimer

SummaryIn order to study the acute and prolonged effects of hypoglycemia on the hemostatic and fibrinolytic system we measured prothrombin fragment (F1+2), thrombin-antithrombin III complex (TAT), platelet factor 4 (PF4), β-thromboglobulin (âTG), factor VIII antigen (F VIII antigen), D-dimer, tissue-type plasminogen activator (t-PA) antigen, and plasminogen activator inhibitor (PAI-1) in 22 patients during insulin tolerance test. F1+2 and TAT increased significantly 15 and 90 minutes after administration of insulin, as did PF4 and âTG. At 4 and 24 hours, these parameters were not different from baseline. Factor VIII antigen was not significantly altered. D-dimer concentration did not change. However, the D-dimer/TAT ratio significantly decreased at 15 and 90 minutes but increased markedly above baseline at 4 and 24 hours. t-PA antigen was also found to be elevated at 15 and 90 minutes but had returned to baseline at 4 and 24 hours. PAI-1 concentration did not change. We conclude from these data that both coagulation and fibrinolysis are activated in the short-term response to acute insulin-induced hypoglycemia, followed by a prolonged activation of fibrinolysis. Our study may explain why patients undergoing insulin tolerance test, despite marked clotting and platelet activation, almost never develop thromboembolic complications.

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