Association between posttest dexamethasone and cortisol concentrations in the 1 mg overnight dexamethasone suppression test

It has been suggested that comparison of posttest dexamethasone and cortisol concentrations may improve the evaluation of the dexamethasone suppression test (DST) for Cushing's syndrome. In particular, this would be reasonable if posttest cortisol differs by dexamethasone levels within the range that is usually attained in the DST. Using fractional polynomial regression, we therefore studied the association between posttest 0800 h dexamethasone and cortisol levels in 53 subjects without Cushing's syndrome who were tested with the 1 mg overnight DST. Plasma dexamethasone was associated with plasma cortisol (P<0.001), and the regression line suggested a strong negative association related to dexamethasone levels <5 nmol/l. However, among the 94% of subjects with plasma dexamethasone >5.0 nmol/l, there was no association between dexamethasone and cortisol levels (P=0.55). In conclusion, subjects tested with the 1 mg overnight DST usually attain an 0800 h plasma dexamethasone >5 nmol/l, and plasma cortisol does not differ by plasma dexamethasone in these subjects. This suggests that routine comparison of dexamethasone and cortisol levels may not be a useful approach to improve the performance of the 1 mg DST. However, dexamethasone measurements may identify subjects with inadequately low plasma dexamethasone and may therefore be of value when retesting subjects with possibly false-positive DST results.

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Clinical Characteristics of Endogenous Cushing’s Syndrome at a Medical Center in Southern Taiwan

International Journal of Endocrinology ◽

10.1155/2013/685375 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Shih-Chen Tung ◽

Pei-Wen Wang ◽

Rue-Tsuan Liu ◽

Jung-Fu Chen ◽

Ching-Jung Hsieh ◽

...

Keyword(s):

Differential Diagnosis ◽

Cushing’S Syndrome ◽

Plasma Cortisol ◽

Medical Center ◽

Cushing's Syndrome ◽

Dexamethasone Suppression Test ◽

Adrenocortical Adenoma ◽

Suppression Test ◽

Southern Taiwan ◽

Dexamethasone Suppression

From January 1987 to December 2011, over a total of 25 years, 84 patients with Cushing’s syndrome (CS) were identified at a medical center in southern Taiwan. We observed a higher incidence of ACTH-independent CS (75%) than ACTH-dependent CS (25%). A higher incidence of adrenocortical adenoma (58.3%) than Cushing’s disease (CD, 21.4%) was also found. The sensitivity of the definitive diagnostic tests for CS, including loss of plasma cortisol circadian rhythm, a baseline 24 h urinary free cortisol (UFC) value >80 μg, and overnight and 2-day low-dose dexamethasone suppression test, was between 94.4% and 100%. For the 2-day high-dose dexamethasone suppression test for the differential diagnosis of CD, the sensitivity of 0800 h plasma cortisol and 24 h UFC was 44.4% and 85.7%, respectively. For the differential diagnosis of adrenal CS, the sensitivities of the 0800 h plasma cortisol and 24 h UFC were 95.5% and 88.9%, respectively. In patients with ACTH-independent CS and ACTH-dependent CS, the baseline plasma ACTH levels were all below 29 pg/mL and above 37 pg/mL, respectively. The postsurgical hospitalization stay following retroperitoneoscopic adrenalectomy was shorter than that observed for transabdominal adrenalectomy (4.3 ± 1.6 versus 8.8 ± 3.7 days,P<0.001). It was easy to develop retroperitoneal and peritoneal seeding of adrenocortical carcinoma via laparoscopic adrenalectomy.

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Influence of sex, body mass index and age on the results of the 2-mg overnight dexamethasone suppression test

LaboratoriumsMedizin ◽

10.1515/labmed-2017-0024 ◽

2017 ◽

Vol 41 (1) ◽

Author(s):

Benjamin Sandner ◽

Jürgen Kratzsch

Keyword(s):

Body Mass Index ◽

Body Mass ◽

Cushing’S Syndrome ◽

Cushing's Syndrome ◽

Dexamethasone Suppression Test ◽

Obese Patients ◽

Suppression Test ◽

Cortisol Levels ◽

Dexamethasone Suppression ◽

Positive Results

AbstractBackground:The overnight dexamethasone suppression test (DST) is routinely used in establishing the diagnosis of Cushing’s syndrome. However, factors such as variable resorption and increased metabolism of dexamethasone (DXMS) could lead to false positive results. The aim of our study was to evaluate the influence of sex, body mass index (BMI) and age on the DXMS metabolism.Methods:In total, 183 subjects were enrolled in a regular 2 mg DST. Patients with Cushing’s syndrome, depression, renal or hepatic insufficiency and patients treated with liver enzyme modulating pharmaceuticals were excluded from this study, so that 72 patients and 66 healthy subjects were analyzed. Nocturnal blood withdrawals were performed in 11 adult subjects at 1:00 AM, 3:00 AM, 5:00 AM, 7:00 AM, 8:00 AM to evaluate the kinetic of DXMS and cortisol.Results:In the DST DXMS levels demonstrated a high variation at 8:00 AM, that was inversely correlated with BMI (r=−0.24, p=0.045). Furthermore, DXMS levels determined in patients with a BMI<30 kg/m2(n=29) were significantly higher than values of obese patients with a BMI>30 kg/m2(n=43) (1.66±0.71 ng/mL vs. 1.31±0.57 ng/mL, p=0.026). Cortisol levels, measured at the same time, were neither correlated with DXMS nor with BMI values. In the kinetic study, maximal DXMS concentration was measured at approximately 3:00 AM. At 8:00 AM, median of DXMS was reduced to 59.1% and was correlated directly with the DXMS AUC (r=0.75, p=0.013). However, there was no correlation between the cortisol levels at 8:00 AM and the nocturnal DXMS concentrations.Conclusions:In the DST BMI of individual patients could modulate the resorption rate and metabolism of DXMS but appears to have no impact on cortisol levels. Therefore, obesity should not be a cause of falsely positive results in the DST.

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Overnight dexamethasone suppression test: comparison of plasma and salivary cortisol measurement for the screening of Cushing's syndrome

Acta Endocrinologica ◽

10.1530/eje.0.1340093 ◽

1996 ◽

Vol 134 (1) ◽

pp. 93-96 ◽

Cited By ~ 28

Author(s):

Zina Barrou ◽

Dominique Guiban ◽

Amel Maroufi ◽

Claudine Fournier ◽

Marie-Annick Dugué ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Cushing’S Syndrome ◽

Salivary Cortisol ◽

Screening Test ◽

Plasma Cortisol ◽

Cushing's Syndrome ◽

Dexamethasone Suppression Test ◽

Suppression Test ◽

Dexamethasone Suppression ◽

Normal Controls

Barrou Z, Guiban D, Maroufi A, Fournier C, Dugué M-A, Luton J-P. Thomopoulos P. Overnight dexamethasone suppression test: comparison of plasma and salivary cortisol measurement for the screening of Cushing's syndrome. Eur J Endocrinol 1996:134:93–6. ISSN 0804–4643 The overnight 1-mg dexamethasone suppression test is a very good screening test for subjects suspected of having Cushing's syndrome. To simplify the procedure, we evaluated the 1-mg dexamethasone suppression test with measurement of salivary cortisol. We performed this test with plasma and salivary cortisol measurements in 27 patients with Cushing's syndrome and 64 normal controls. The sensitivity and specificity of plasma cortisol measurements were 100% and 87%, respectively, for a cut-off point of 100 nmol/l, in accordance with previous studies. The results of salivary cortisol showed the absence of overlap between the two groups, with a sensitivity and specificity of 100% for a cut-off point of 2.8 nmol/l, On a larger series, however, one might occasionally miss the diagnosis of a patient with Cushing's syndrome. Therefore, we favor a cut-off point of 1.9 nmol/l, the sensitivity remaining at 100% and the specificity being 94%. In conclusion we recommend the overnight dexamethasone suppression test with measurement of salivary cortisol as a screening test for Cushing's syndrome. Pierre Thomopoulos. Clinique des maladies endocriniennes et métaboliques. Hôpital Cochin, 27 rue du Faubourg Saint-Jacques, 75014 Paris, France

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SIMPLIFIED DEXAMETHASONE SUPPRESSION TEST

Acta Endocrinologica ◽

10.1530/acta.0.0610219 ◽

1969 ◽

Vol 61 (2) ◽

pp. 219-231 ◽

Cited By ~ 14

Author(s):

V. H. Asfeldt

Keyword(s):

Cushing’S Syndrome ◽

Normal Subjects ◽

Cushing's Syndrome ◽

Dexamethasone Suppression Test ◽

Clinical Value ◽

Suppression Test ◽

The One ◽

Steroid Excretion ◽

Dexamethasone Suppression

ABSTRACT This is an investigation of the practical clinical value of the one mg dexamethasone suppression test of Nugent et al. (1963). The results, evaluated from the decrease in fluorimetrically determined plasma corticosteroids in normal subjects, as well as in cases of exogenous obesity, hirsutism and in Cushing's syndrome, confirm the findings reported in previous studies. Plasma corticosteroid reduction after one mg of dexamethasone in cases of stable diabetes was not significantly different from that observed in control subjects, but in one third of the insulin-treated diabetics only a partial response was observed, indicating a slight hypercorticism in these patients. An insufficient decrease in plasma corticosteroids was observed in certain other conditions (anorexia nervosa, pituitary adenoma, patients receiving contraceptive or anticonvulsive treatment) with no hypercorticism. The physiological significance of these findings is discussed. It is concluded that the test, together with a determination of the basal urinary 17-ketogenic steroid excretion, is suitable as the first diagnostic test in patients in whom Cushing's syndrome is suspected. In cases of insufficient suppression of plasma corticosteroids, further studies, including the suppression test of Liddle (1960), must be carried out.

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