Clinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis.

Hdl Handle:
http://hdl.handle.net/10147/136786
Title:
Clinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis.
Authors:
Finucane, Francis M; Liew, Aaron; Thornton, Evan; Rogers, Barbara; Tormey, William; Agha, Amar
Affiliation:
Academic Department of Endocrinology, Beaumont Hospital and the RCSI Medical School, Dublin, Ireland.
Citation:
Clinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis. 2008, 69 (4):603-7 Clin. Endocrinol. (Oxf)
Journal:
Clinical endocrinology
Issue Date:
Oct-2008
URI:
http://hdl.handle.net/10147/136786
DOI:
10.1111/j.1365-2265.2008.03240.x
PubMed ID:
18346212
Additional Links:
http://www.ncbi.nlm.nih.gov/pubmed/18346212
Abstract:
The insulin tolerance test (ITT) is the gold standard for assessing GH and cortisol production in pituitary disease. However, areas of uncertainty remain regarding its safety in older people, the optimal duration of the test and its performance in insulin resistant states. Whether basal cortisol concentration can reliably predict an adequate adrenal response to hypoglycaemia remains to be determined.; We performed a cross-sectional retrospective examination of 197 consecutive patients (mean age 41.8 +/- 16.4, range 13-76 years) with pituitary disease who underwent the ITT over 18 months. The standard intravenous insulin dose administered was 0.15 units/kg body weight. Patients with acromegaly or with type 2 diabetes received 0.2 units/kg; those with basal cortisol < 100 nmol/l received 0.1 units/kg.; Adequate hypoglycaemia (nadir glucose < 2.2 mmol/l) was achieved in 87% of patients, amongst whom 17% did not achieve peak cortisol until 120 min. There were no significant adverse events, even in those >or= 65 years. Of the 18 patients who had basal cortisol < 100 nmol/l, 78% achieved adequate hypoglycaemia; 29% of those had an adequate peak cortisol response >or= 500 nmol/l. A receiver operating characteristics curve identified a basal cortisol of >or= 393 nmol/l to predict a normal peak cortisol response to hypoglycaemia.; In specialized units, the ITT is safe even in elderly patients and those with hypocortisolaemia. The standard 90-min. cut-off for the ITT misses one in six peak cortisol responses. Some patients with basal cortisol < 100 nmol/l had a normal cortisol response to hypoglycaemia.
Item Type:
Article
Language:
en
MeSH:
Adenoma; Adolescent; Adult; Aged; Cross-Sectional Studies; Female; Glucose Clamp Technique; Humans; Hypothalamo-Hypophyseal System; Insulin; Male; Middle Aged; Pituitary Neoplasms; Pituitary-Adrenal Function Tests; Pituitary-Adrenal System; Predictive Value of Tests; Prognosis; Retrospective Studies; Young Adult
ISSN:
1365-2265

Full metadata record

DC FieldValue Language
dc.contributor.authorFinucane, Francis Men
dc.contributor.authorLiew, Aaronen
dc.contributor.authorThornton, Evanen
dc.contributor.authorRogers, Barbaraen
dc.contributor.authorTormey, Williamen
dc.contributor.authorAgha, Amaren
dc.date.accessioned2011-07-25T08:37:55Z-
dc.date.available2011-07-25T08:37:55Z-
dc.date.issued2008-10-
dc.identifier.citationClinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis. 2008, 69 (4):603-7 Clin. Endocrinol. (Oxf)en
dc.identifier.issn1365-2265-
dc.identifier.pmid18346212-
dc.identifier.doi10.1111/j.1365-2265.2008.03240.x-
dc.identifier.urihttp://hdl.handle.net/10147/136786-
dc.description.abstractThe insulin tolerance test (ITT) is the gold standard for assessing GH and cortisol production in pituitary disease. However, areas of uncertainty remain regarding its safety in older people, the optimal duration of the test and its performance in insulin resistant states. Whether basal cortisol concentration can reliably predict an adequate adrenal response to hypoglycaemia remains to be determined.-
dc.description.abstractWe performed a cross-sectional retrospective examination of 197 consecutive patients (mean age 41.8 +/- 16.4, range 13-76 years) with pituitary disease who underwent the ITT over 18 months. The standard intravenous insulin dose administered was 0.15 units/kg body weight. Patients with acromegaly or with type 2 diabetes received 0.2 units/kg; those with basal cortisol < 100 nmol/l received 0.1 units/kg.-
dc.description.abstractAdequate hypoglycaemia (nadir glucose < 2.2 mmol/l) was achieved in 87% of patients, amongst whom 17% did not achieve peak cortisol until 120 min. There were no significant adverse events, even in those >or= 65 years. Of the 18 patients who had basal cortisol < 100 nmol/l, 78% achieved adequate hypoglycaemia; 29% of those had an adequate peak cortisol response >or= 500 nmol/l. A receiver operating characteristics curve identified a basal cortisol of >or= 393 nmol/l to predict a normal peak cortisol response to hypoglycaemia.-
dc.description.abstractIn specialized units, the ITT is safe even in elderly patients and those with hypocortisolaemia. The standard 90-min. cut-off for the ITT misses one in six peak cortisol responses. Some patients with basal cortisol < 100 nmol/l had a normal cortisol response to hypoglycaemia.-
dc.language.isoenen
dc.relation.urlhttp://www.ncbi.nlm.nih.gov/pubmed/18346212en
dc.subject.meshAdenoma-
dc.subject.meshAdolescent-
dc.subject.meshAdult-
dc.subject.meshAged-
dc.subject.meshCross-Sectional Studies-
dc.subject.meshFemale-
dc.subject.meshGlucose Clamp Technique-
dc.subject.meshHumans-
dc.subject.meshHypothalamo-Hypophyseal System-
dc.subject.meshInsulin-
dc.subject.meshMale-
dc.subject.meshMiddle Aged-
dc.subject.meshPituitary Neoplasms-
dc.subject.meshPituitary-Adrenal Function Tests-
dc.subject.meshPituitary-Adrenal System-
dc.subject.meshPredictive Value of Tests-
dc.subject.meshPrognosis-
dc.subject.meshRetrospective Studies-
dc.subject.meshYoung Adult-
dc.titleClinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis.en
dc.typeArticleen
dc.contributor.departmentAcademic Department of Endocrinology, Beaumont Hospital and the RCSI Medical School, Dublin, Ireland.en
dc.identifier.journalClinical endocrinologyen
dc.description.provinceLeinster-
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