The 4-mg intravenous dexamethasone suppression test in the diagnosis of Cushing's syndrome.
Clin Endocrinol (Oxf)
; 73(1): 78-84, 2010 Jul.
Article
em En
| MEDLINE
| ID: mdl-20039897
ABSTRACT
OBJECTIVE:
Optimal diagnostic criteria for the 4-mg intravenous dexamethasone suppression test (IVDST) in patients with Cushing's syndrome (CS), compared with normal subjects, have not been established. We evaluated the performance of the 4-mg IVDST for differentiating CS from normal subjects and to define the responses in CS of various aetiologies. DESIGN, SUBJECTS, MEASUREMENTS Thirty-two control subjects [normal and overweight/obese participants with or without type 2 diabetes) were prospectively studied, and data from 66 patients with Cushing's disease (CD), three with ectopic ACTH syndrome (EAS), 14 with adrenal Cushing's (AC)] and 15 with low probability of CS (LPC) from three tertiary hospitals were retrospectively evaluated. Dexamethasone was infused at 1 mg/h for 4 h. Plasma cortisol and ACTH were measured at -60 min (baseline), -5 min, +3 h, +4 h, +5 h and at +23 and +23.5 h on Day 2.RESULTS:
Control subjects (including those with type 2 diabetes) exhibited a marked suppression of cortisol which was maintained until Day 2. Two of 15 patients with LPC had Day 2 cortisol results that overlapped with CS. Patients with CD demonstrated partial suppression, with rebound hypercortisolism on Day 2. Patients with AC and EAS did not suppress cortisol levels. Day 2 cortisol level of >130 nmol/l (or >20% of the baseline) diagnosed CS with 100% sensitivity and 96% specificity.CONCLUSION:
While the IVDST allowed complete discrimination between control subjects and CS, 13% of LPC overlapped with CS. Given the small number of EAS, no conclusion can be drawn regarding the utility of this test in the differential diagnosis of CS.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Dexametasona
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Síndrome de Cushing
Tipo de estudo:
Diagnostic_studies
/
Evaluation_studies
Limite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article