Postsurgical Recurrent Cushing Disease: Clinical Benefit of Early Intervention in Patients with Normal Urinary Free Cortisol

Objective: To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC).Methods: The design was a single-center, retrospective chart review. Patients treated by the authors from 2008–2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST).Results: We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements.Conclusion: LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker.Abbreviations:ACTH = adrenocorticotropic hormoneCD = Cushing diseaseCS = Cushing syndromeCV = coefficient of variationDST = dexamethasone suppression testIPSS = inferior petrosal sinus samplingLNSC = late-night salivary cortisolQoL = quality of lifeTSS = transsphenoidal adenoma resectionUFC = urinary free cortisol     

Topiramate as a Cause of False Positive in the Overnight 1-Mg Dexamethasone Suppression Test

ObjectiveTo describe that topiramate may cause a false positive in an overnight 1-mg dexamethasone suppression test (DST) for hypercortisolism screening.MethodsWe present a case in which topiramate induced dexamethasone metabolism, leading to a false positive on the DST.ResultsA 44-year-old female with an incidentally found adenoma in the right adrenal gland underwent a DST for hypercortisolism screening. The patient was taking topiramate prescribed by a psychiatrist for an affective disorder, and insufficient cortisol suppression (11.9 mcg/ dL) was observed. Her free cortisol in 24-hour urine was normal, and insufficient suppression was established in a second determination (9.3 mcg/dL). Finally, her psychiatrist switched her treatment from topiramate to bupropion, and the measurements were repeated. When she was not taking topiramate, correct suppression with 1 mg of dexamethasone was obtained (1.7 mcg/dL), and her free cortisol in 24-hour urine was again normal, thereby excluding the presence of hypercortisolism. On reviewing the literature, topiramate was not found to have been previously described as a cause of a false positive on DST, but it was proposed as a cause of hypoadrenalism in a patient taking oral corticosteroid replacement due to its capacity to induce dexamethasone metabolism.ConclusionTopiramate treatment may well be a cause of false positives in DSTs, and its presence should be taken into consideration when screening for hypercortisolism. (Endocr Pract. 2014;20:e116-e118)     

Overnight Dexamethasone Suppression Test: A Reliable Screen for Cushing's Syndrome in the Obese

Objective: Reevaluation of the validity of the 1-mg overnight dexamethasone suppression test (ODST) as a screening test for Cushing's syndrome in obese patients. Research Methods and Procedures: Eighty-six obese patients (body mass index, 30 to 53 kg/m²) that were referred to a general endocrine outpatient clinic for evaluation of simple obesity, diabetes mellitus, hypertension, polycystic ovary disease, or pituitary tumor. One milligram dexamethasone was administered orally at 11:00 pm , and serum cortisol levels were measured the following morning between 8:00 am and 9:00 am . Suppression of serum cortisol to <80 nM (3 μg/dL) was chosen as the cut-off point for normal suppression. Patients with serum cortisol levels ≥80 nM were evaluated for Cushing's syndrome. Results: Suppression of morning cortisol levels to <80 nM occurred in 79 of the 86 obese patients. Seven patients had serum cortisol levels higher than 80 nM; five were eventually diagnosed with Cushing's syndrome and two were considered false positive results in view of normal 24-hour free urinary cortisol and normal suppression on a low dose dexamethasone suppression test (0.5 mg of dexamethasone every 6 hours for 2 days). We found a false positive rate of 2.3% for the ODST using a cut-off serum cortisol of 80 nM. Discussion: The ODST is a valid screening test for Cushing's syndrome in the obese population. The false positive rate was 2.3%, even when using a strict cut-off serum cortisol of 80 nM. Abnormal cortisol suppression in obese patients should be investigated and not be considered false positive results.     

Cushing’s Disease and Pregnancy: Case Report and Literature Review

ObjectiveTo describe a patient with untreated Cushing’s disease who had 2 spontaneous pregnancies that resulted in healthy babies on both occasions.MethodsWe present a case report with clinical, laboratory, and imaging data and discuss the literature pertaining to pregnancy in patients with Cushing’s syndrome.ResultsA 28-year-old woman came to our endocrinology clinic with a 1-year history of symptoms and signs of Cushing’s syndrome. An elevated 24-hour urinary cortisol excretion and an unsuppressed 1-mg overnight dexamethasone test confirmed the diagnosis. On her next visit, she reported a confirmed pregnancy, which ultimately resulted in the birth of a normal child. Further work-up subsequently showed 2 elevated 24-hour urinary cortisol values, loss of diurnal variation, and an elevated corticotropin level. There was lack of suppression on low-dose and high-dose overnight dexamethasone suppression tests. Magnetic resonance imaging of the pituitary showed normal findings. Inferior petrosal sinus sampling was recommended, but she declined the procedure. The patient returned 3 years later for reevaluation, at which time she reported the birth of another healthy child by cesarean delivery 10 months previously. There were no reported maternal or fetal complications. Examination at this visit revealed buccal pigmentation and proximal myopathy. Investigations showed increased 24-hour urinary cortisol excretion and serum corticotropin levels. Repeated magnetic resonance imaging disclosed a microadenoma on the right side of the pituitary. Unstimulated inferior petrosal sinus sampling showed a gradient to the right; thus, the presence of pituitary-dependent Cushing’s disease was confirmed.ConclusionOur case demonstrates that patients with pituitary-dependent Cushing’s disease are more likely to have spontaneous pregnancies with favorable outcomes than are patients with Cushing’s syndrome due to other causes. Our patient, despite having Cushing’s disease for more than 7 years, had 2 uneventful pregnancies that produced normal healthy children, without exacerbation of her disease during pregnancy. (Endocr Pract. 2007;13: 296-299)     

Overnight (1 mg) dexamethasone suppression testing reliably distinguishes non-cushingoid obesity from Cushing's syndrome.

To determine the sensitivity of the overnight 1-mg dexamethasone suppression test in diagnosing Cushing's syndrome, we evaluated the cortisol responses of 55 subjects (25 non-obese individuals with body mass index less than 25 kg/m2, 20 obese individuals with body mass index greater than 30 kg/m2, and 10 patients with surgically proven Cushing's syndrome) following ingestion of 1 mg dexamethasone at midnight. The basal 8 AM plasma cortisol levels among non-obese and obese individuals and patients with Cushing's syndrome were 310 +/- 85, 377 +/- 91, and 813 +/- 270 nmol/L, respectively. Following 1 mg of dexamethasone, Cushing's syndrome patients showed minimal suppression of cortisol to 609 +/- 180 nmol/L (P = 0.79). Non-obese and obese individuals suppressed to 18.7 +/- 6.0 nmol/L (P less than 0.001) and 22 +/- 7.1 nmol/L (P = 0.003), respectively. The results demonstrated similar cortisol responses to overnight dexamethasone suppression in obese and non-obese groups, and clearly distinguished these subjects from those with Cushing's syndrome. Obesity is not a confounding factor in the 1-mg dexamethasone suppression test.     

The changes in plasma cortisol and urinary free cortisol by an overnight dexamethasone suppression test in patients with Cushing's disease

We studied the suppressibility of cortisol secretion in 15 patients with Cushing's disease by measuring morning plasma cortisol level as well as the 24-hour urinary free corisol (UFC) excretion following single doses of increasing amounts of dexamethasone (ranging from 0.5 to 32 mg) given at 11 p.m. The mean plasma cortisol level in patients with Cushing's disease was twice as high as in normal subjects, whereas the mean UFC in these patients was 6 times as high. Plasma cortisol in seven patients were suppressed by less than 4 mg of dexamethasone (in 2 cases, less than 0.5 mg; in 3 cases, less than 2 mg; and in 2 cases less than 4 mg). In these cases, basal plasma cortisol and UFC were less than 25 micrograms/dl and 350 micrograms/day, respectively. Among the other eight patients, plasma cortisol was partially suppressed in 5 cases and not suppressed in 3 cases by high doses of dexamethasone (16-32 mg). In these cases the basal plasma cortisol and UFC were more than 25 micrograms/dl and 350 micrograms/day, respectively. There was a significant correlation between the basal plasma cortisol and UFC (r = 0.687, p less than 0.01). These data suggest that the suppression by increasing amounts of dexamethasone in most cases with Cushing's disease was related to the severity of hypercortisolism.     

Low Diagnostic Utility of Overnight High-Dose Dexamethasone Suppression Test in ACTH-Dependent Cushing’s Syndrome

ObjectiveOvernight high-dose dexamethasone suppression test (ON-HDDST) is a simple test to localize the source of ACTH in patients with ACTH-dependent Cushing’s syndrome (CS). However, previous studies have reported its varying accuracy. We studied the utility of ON-HDDST in diagnosing Cushing’s disease (CD) in a series of patients with CD and ectopic ACTH syndrome (EAS).MethodsWe conducted a retrospective study of 88 patients with ACTH-dependent CS (plasma ACTH > 20.0 pg/mL), who underwent an ON-HDDST. CD and EAS were diagnosed in 68 and 20 patients, respectively. Patients were investigated using MRI of the sellar region, CT of the thorax/abdomen, Gallium-68-DOTANOC PET scan, and bilateral inferior petrosal sinus sampling as required.ResultsPatients with EAS had a significantly higher serum cortisol after ON-HDDST than patients with CD (median [IQR], 19.9 [12.4-31.1] μg/dL vs 9.9 [5.1-25.0] μg/dL, P <.01). A suppressed ON-HDDST (≥50% fall from baseline) was noted in 44 (65%) patients with CD and 3 (15%) patients with EAS (P <.0001). Among patients with CD, cortisol suppression >50% was noted in 35 (76%) of patients with microadenoma and 7 (44%) with macroadenoma. Among patients with EAS, ON-HDDST was suppressed in 1 of 6 patients (17%) with an occult tumor and 2 of 14 patients (14%) with a localized tumor. The ROC curve plotted for the percentage suppression of cortisol had an area under the curve (AUC) of 0.72 (P =.01). The best test parameters, with 65% sensitivity, 85% specificity, 94% positive predictive value, 42% negative predictive value, and 69% accuracy, were at 50% cutoff level.ConclusionThe ON-HDDST had a poor diagnostic value in differentiating CD and EAS.     

Utility of a Single Late-Night Plasma Cortisol and Acth for the Diagnosis of Cushing Syndrome

Objective: To evaluate the diagnostic efficacy of various screening tests for the diagnosis of Cushing syndrome (CS).Methods: Thirty-five patients with CS and 16 patients of pseudo-CS were enrolled. Assessment of 24-h urinary free cortisol (UFC), late-night salivary cortisol (LNSC), overnight dexamethasone suppression test (ONDST), late-night plasma cortisol (LNPC), and adrenocorticotropic hormone (ACTH) on outpatient basis, and during sleep as well as in awake state after 48 hours of hospital admission.Results: We found that 24-h UFC performed the best among the screening tests with sensitivity, specificity and areas under the curve (AUCs) of 96.0%, 99%, and 0.988, respectively, at a cut-off of 144.6 μg/24 h. A cut-off of 10.5 nmol/L for LNSC had sensitivity 85.7%, specificity 88.2%, and an AUC of 0.897. A cut-off of 412.4 nmol/L for LNPC on outpatient basis had sensitivity 88.2%, specificity 91.2%, and an AUC of 0.957. Cut-offs of 215 and 243.3 nmol/L for LNPC during sleep and awake states after acclimatization had sensitivity, specificity, and an AUC of 94.1%, 88.2%, and 0.958, respectively. An ONDST cut-off of 94.6 nmol/L provided sensitivity, specificity, and an AUC of 96.0%, 99.03% and 0.995, respectively. A cut-off of 30.3 pg/mL for late-night ACTH on outpatient basis had sensitivity 67.6%, specificity 99.9%, and an AUC 0.796.A cut-off of 22.6 pg/mL for ACTH during sleep state after acclimatization had sensitivity, specificity, and an AUC of 73.5%, 99.2%, and 0.827, respectively.Conclusion: UFC is the best screening test for CS. Furthermore, single measurements of LNPC and ACTH help to establish the diagnosis and ACTH dependency of CS in the majority of patients with CS.Abbreviations:ACTH = adrenocorticotropic hormoneAUC = area under the curveCRH = corticotropin-releasing hormoneCS = Cushing syndromeECLIA = electrochemiluminescence immuno-assayLDDST = low-dose dexamethasone suppression testLNPC = late-night plasma cortisolLNSC = late-night salivary cortisolONDST = overnight dexamethasone suppression testRIA = radio-immuno assayUFC = urinary free cortisol     

Virilizing Ovarian Leydig Cell Tumor in A Woman with Subclinical Cushing Syndrome

ObjectiveTo report the case of a patient with a virilizing ovarian Leydig cell tumor and subclinical Cushing syndrome attributable to an adrenal adenoma.MethodsDetailed clinical, laboratory, radiologic, and pathologic findings are presented, and the pertinent literature is reviewed.ResultsA 49-year-old woman was referred for evaluation of a left adrenal mass (3.0 by 2.4 cm), which had been diagnosed by computed tomographic scan 4 years previously during a work-up for hirsutism. On examination, she had central obesity, facial hirsutism, and male pattern baldness. Work-up showed elevated total and free testosterone levels of 196 ng/dL (reference range, 20 to 70) and 24 pg/mL (1 to 9), respectively. Other results (and reference ranges) were as follows: dehydroepiandrosterone sulfate, 7.5 μg/dL (10 to 221); corticotropin, 12 pg/mL (5 to 50); morning cortisol, 1.4 μg/dL after a 1-mg overnight dexamethasone suppression test; and urine free cortisol, 48.8 μg/24 h (20 to 100). The testosterone level decreased by 14% after a 2-day low-dose dexamethasone suppression test. Findings on transvaginal ovarian ultrasonography and a computed tomographic scan of the pelvis were normal. A laparoscopic adrenalectomy revealed an adrenal adenoma. On the first day postoperatively, the cortisol level was less than 1.0 μg/dL; however, the testosterone level remained elevated. At 6 months postoperatively, a normal result of a cosyntropin stimulation test indicated recovery of the hypothalamic-pituitaryadrenal axis. Bilateral oophorectomy revealed a 1.3-cm right ovarian Leydig cell tumor. Postoperatively, the testosterone level declined to less than 20 ng/dL.ConclusionTo our knowledge, this is the first case report of a virilizing ovarian Leydig cell tumor in a patient with subclinical Cushing syndrome. (Endocr Pract. 2008;14:358-361)     

Diurnal variation of 6beta-hydroxycortisol in cardiac patients

The 24-hour urinary excretion of 6-beta-hydroxycortisol (6beta-OHC) and the urinary ratio of 6beta- hydroxycortisol/cortisol (6beta-OHC/UFC) have been proposed as noninvasive probes for human cytochrome P450 3A4 isoform (CYP3A4). In this study, we evaluated within- and between-day variability of 6beta-OHC excretion and 6beta-OHC/UFC ratio in nine Caucasian men with cardiac disease. Each study participant was asked to collect 24-hour urine specimens during four consecutive days in five standardized time intervals. Concentrations of UFC and 6beta-OHC were determined by immunoassay and the high-performance liquid chromatographic (HPLC) method, respectively. The HPLC method was accurate and precise, as indicated by the recovery rate of 96.5-103.3 % and less than 5.2 % and 6.3 % of the coefficient of variation for within-run and between-run assay, respectively. In patients, diurnal variations in UFC and 6beta-OHC excretion were parallel. Consequently, 6beta-OHC/UFC ratio remained stable during the day. Both, 6beta-OHC excretion and 6beta-OHC/UFC ratio showed significant relationship between 24-hour value and values measured in corresponding collection periods with best correlations obtained from night interval (22.00-06.00, r = 0.86-0.91). These results indicated that urinary 6beta-OHC excretion and 6beta-OHC/UFC ratio measured in overnight/morning urine could precisely reflect 24-hour values even in severely ill patients. In addition, a simple and sensitive HPLC method was described for determination of 6beta-OHC in urine.     

Single-dose four hour dexamethasone suppression test in normal men and its application for the diagnosis of cushing's syndrome

As a four hour morning test, plasma cortisol levels were radioimmunoassayed before and at two and four hours after dexamethasone (0, 0.5 mg, 1.0 mg or 2.0 mg) was administered at 8–9 a.m. in 20 normal subjects. The 1.0 mg four hour test was most effective in suppression of cortisol and it showed the same suppressibility as the widely used single-dose overnight test. With the 1.0 mg four hour test, 2 patients with Cushing's syndrome due to adrenal hyperplasia could be differentiated from normal and obese subjects.The four hour morning test would be more useful than the widely used overnight test from the reasons; i) it shows the same suppressibility as the overnight test, ii) it obviates the need for bothersome midnight administration of dexamethasone, iii) because it takes only one morning to perform, it can save a day, iv) and it might be applicable for the differential diagnosis of Cushing's syndrome because 4.0 mg morning test resulted in complete suppression of plasma cortisol in a tested Cushing's syndrome, whereas with even 8.0 mg, plasma cortisol was not suppressed in the overnight test in 2 such patients examined.     

Pituitary Mri Findings in Patients With Pituitary and Ectopic Acth-Dependent Cushing Syndrome: Does A 6-Mm Pituitary Tumor Size Cut-Off Value Exclude Ectopic Acth Syndrome?

Objective: Expert opinion and a consensus statement on Cushing syndrome (CS) indicate that in a patient with a clinical presentation and biochemical studies consistent with a pituitary etiology, the presence of a pituitary tumor ≥6 mm is highly suggestive of Cushing disease (CD). The purpose of the present study was to determine the optimal pituitary tumor size that can differentiate between patients with CD and ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS) and obviate the need for inferior petrosal sinus sampling (IPSS).Methods: We performed a retrospective study of 130 patients seen between 2000 and 2012 including 104 patients with CD and 26 patients with EAS.Results: A pituitary lesion was reported in 6/26 (23%) patients with EAS and 71/104 (68.3%) patients with CD, with median (range) sizes of 5 mm (3–14) and 8 mm (2–31), respectively. All tumors in the EAS group measured ≤6 mm except for 1 that measured 14 mm. The presence of a pituitary tumor >6 mm in size had 40% sensitivity and 96% specificity for the diagnosis of CD. ACTH levels >209 pg/mL and serum potassium <2.7 mmol/L were found in patients with EAS. All patients with EAS had a 24-hour urine free cortisol (UFC) >3.4 times the upper limit of normal (×ULN)Conclusion: Pituitary incidentalomas as large as 14 mm in size can be seen in patients with EAS. However, the 6-mm tumor size cut-off value provided 96% specificity and may be a reasonable threshold to proceed with surgery without the need for IPSS when the biochemical data support a pituitary etiology.Abbreviations: ACTH = adrenocorticotropic hormone CD = Cushing disease CRH = corticotropin-releasing hormone CS = Cushing syndrome EAS = ectopic ACTH secretion IPSS = inferior petrosal sinus sampling HDDST = high-dose dexamethasone suppression test LDDST = low-dose dexamethasone suppression test MRI = magnetic resonance imaging UFC = urine free cortisol ULN = upper limit of normal     

Results of repeated transsphenoidal surgery in Cushing's disease. Long-term follow-up

ObjectiveTranssphenoidal surgery (TSS) is the treatment of choice for Cushing's disease (CD). However, the best treatment option when hypercortisolism persists or recurs remains unknown. The aim of this study was to analyze the short and long-term outcome of repeat TSS in this situation and to search for response predictors.Patients and methodsData from 26 patients with persistent (n = 11) or recurrent (n = 15) hypercortisolism who underwent repeat surgery by a single neurosurgeon between 1982 and 2009 were retrospectively analyzed. Remission was defined as normalization of urinary free cortisol (UFC) levels, and recurrence as presence of elevated UFC levels after having achieved remission. The following potential outcome predictors were analyzed: adrenal status (persistence or recurrence) after initial TSS, tumor identification in imaging tests, degree of hypercortisolism before repeat TSS, same/different surgeon in both TSS, and time to repeat surgery.ResultsImmediate postoperative remission was achieved in 12 patients (46.2%). Five of the 10 patients with available follow-up data relapsed after surgery (median time to recurrence, 13 months). New hormone deficiencies were seen in seven patients (37%), and two patients had cerebrospinal fluid leakage. No other major complications occurred. None of the preoperative factors analyzed was predictive of surgical outcome.ConclusionsWhen compared to initial surgery, repeat TSS for CD is associated to a lower remission rate and a higher risk of recurrence and complications. Further studies are needed to define outcome predictors.     

Significant Hypercortisolism During Fractionated Radiotherapy in a Patient with a Large Corticotroph Adenoma: A Case Report and Literature Review

ObjectiveWe describe a patient with a large, invasive corticotroph adenoma who developed severe hypercortisolism shortly after starting fractionated radiotherapy.MethodsWe reviewed the patient’s clinical course, along with relevant literature for similar reported cases.ResultsA 29-year-old man was referred for radiotherapy for a residual and recurrent, invasive corticotroph adenoma. Prior to radiotherapy, he had a normal urine free cortisol (UFC) level of 44.7 μg/24 hours, with minimal symptoms. Within 2 weeks of radiotherapy, he developed hypertension, ankle edema, and hypokalemia (potassium level, 2.8 mEq/L), with a markedly elevated UFC level of 9,203 μg/24 hours. His UFC gradually decreased and normalized by the end of radiotherapy. One month later, the patient became adrenal insufficient, with a nondetectable 24-hour UFC. His adrenal function slowly recovered in 3 months. We are aware of only one previous case report of clinically significant hypercortisolism following radiotherapy in Cushing disease.ConclusionRadiotherapy may result in acute severe hypercortisolism in patients with a large corticotroph adenoma. This uncommon, but clinically significant, acute adverse effect of radiotherapy suggests that clinical observation and biochemical monitoring during or soon after radiotherapy may be indicated. (Endocr Pract. 2014;20:e166-e170)     

The discriminatory value of the low-dose dexamethasone suppression test in the investigation of paediatric Cushing's syndrome

BACKGROUND: Low- and high-dose dexamethasone suppression tests (LDDST, HDDST) are used in the investigation of Cushing's syndrome (CS). In adults with Cushing's disease (CD), cortisol suppression during LDDST predicts suppression during the HDDST. METHODS: We reviewed the results of the LDDST (0.5 mg 6 hourly x 48 h), HDDST (2.0 mg 6 hourly x 48 h) and corticotrophin-releasing hormone (CRH) test in 32 paediatric patients with CS: 24 had CD, 1 ectopic ACTH syndrome, 5 nodular adrenal hyperplasia and 2 adrenocortical tumours. Results: In CD, LDDST suppressed cortisol from 590.7 +/- 168.8 (mean +/- SD) to 333.7 +/- 104.0 nmol/l after 48 h (0 vs. 48 h, p < 0.05; mean suppression, 45.1%; CI (30.8, 59.4%); 16/24 (66%) suppressed >30%; mean suppression 68.1%, CI (58.1, 77.9%)). The HDDST suppressed cortisol from 596.3 +/- 174.5 to 47.1 +/- 94.8 nmol/l after 48 h (0 vs. 48 h, p < 0.05; mean suppression, 93.5%; CI (88.2, 98.8%) with 17/24 (71%) suppressing to <50 nmol/l and 100% to <50% of baseline). In the LDDST, suppression correlated with that during the HDDST (r = +0.45, p < 0.05) with >30% suppression predicting that in the HDDST and hence CD. CRH increased cortisol by +100.3% (CI 62, 138.5%), 22/24 (91.7%) showing a >20% increase. In the other CS pathologies (n = 8) the LDDST induced no significant decrease in cortisol. CONCLUSION: The LDDST was of diagnostic value by discriminating between CD and other CS aetiologies. In our view the HDDST is redundant in the investigation of paediatric CS.     

Lower growth hormone and higher cortisol are associated with greater visceral adiposity, intramyocellular lipids, and insulin resistance in overweight girls

Although body composition, insulin sensitivity, and lipids are markedly altered in overweight adolescents, hormonal associations with these parameters have not been well characterized. Growth hormone (GH) deficiency and hypercortisolemia predispose to abdominal adiposity and insulin resistance, and GH secretion is decreased in obese adults. We hypothesized that low-peak GH on the GH-releasing hormone (GHRH)-arginine stimulation test and high cortisol in overweight adolescents would be associated with higher regional fat, insulin resistance, and lipids. We examined the following parameters in 15 overweight and 15 bone age-matched control 12- to 18-yr-old girls: 1) body composition using dual-energy X-ray absorptiometry and MR [visceral and subcutaneous adipose tissue at L(4)-L(5) and soleus intramyocellular lipid ((1)H-MR spectroscopy)], 2) peak GH on the GHRH-arginine stimulation test, 3) mean overnight GH and cortisol, 4) 24-h urinary free cortisol (UFC), 5) fasting lipids, and 6) an oral glucose tolerance test. Stepwise regression was the major tool employed to determine relationships between measured parameters. Log peak GH on the GHRH-arginine test was lower (P = 0.03) and log UFC was higher (P = 0.02) in overweight girls. Log mean cortisol (overnight sampling) was associated positively with subcutaneous adipose tissue and, with body mass index standard deviation score, accounted for 92% of its variability, whereas log peak GH and body mass index standard deviation score accounted for 88% of visceral adipose tissue variability and log peak GH for 34% of the intramyocellular lipid variability. Log mean cortisol was independently associated with log homeostasis model assessment of insulin resistance, LDL, and HDL and explained 49-59% of the variability. Our data indicate that lower peak GH and higher UFC in overweight girls are associated with visceral adiposity, insulin resistance, and lipids.     

Activated hypothalamic pituitary adrenal axis in patients with metabolic syndrome

Metabolic syndrome (MetS) is correlated with the activity of hypothalamic-pituitary-adrenal axis (HPA), but the underlying mechanism still remains elusive. The aim of this study was to investigate the HPA axis function in patients with MetS. This case-control study included 159 people. They were divided into 2 groups. The first group included 73 healthy volunteers (control group: 19 males, 54 females, mean±SD: 49.9±7.5 years old, with BMI: 27.9±4.42?kg/m2) and the second group included 86 patients with MetS (case group: 48 males, 38 females, mean±SD: 52.2±7.6 years old, with BMI: 30.5±5.35?kg/m2). An oral glucose tolerance test (OGTT) was performed for all subjects after a 12-h overnight fast, and blood samples were obtained for determination of ACTH, cortisol, insulin, C-peptide, and glucose levels. Serum cortisol after an overnight dexamethasone suppression test was determined in both groups. Patients with MetS had serum cortisol levels after an overnight dexamethasone suppression test significantly higher than controls. During OGTT plasma ACTH levels were higher at all time points in patients with MetS compared to controls, whereas serum cortisol levels were comparable between the 2 groups. Plasma ACTH during OGTT was also correlated with most of the components of MetS. The HPA axis in patients with MetS seems to be more active as evidenced by the higher cortisol levels after the overnight dexamethasone suppression test and by the higher ACTH levels during OGTT. This functional hypercortisolism might be involved in the pathogenesis of the metabolic syndrome.     

Influence of amiodarone on urinary excretion of 6beta-hydroxycortisol in humans

The present study was undertaken to evaluate the use of cortisol 6beta-hydroxylation in defining the effect of amiodarone on cytochrome CYP3A activity. To accomplish this goal, the in vivo activity of CYP3A was estimated by measuring the 24-hour urinary excretion of 6beta-hydroxycortisol (6beta-OHC) and by calculating 24-hour ratio of 6beta-hydroxycortisol to urinary free cortisol (6beta-OHC/UFC ratio). Nine cardiac patients scheduled for amiodarone treatment were recruited to participate in this study. Urine was collected over a 24-hour period from each subject before the first amiodarone administration and during the third day of oral administration of amiodarone (200 mg four times daily as a loading dose). Three days of amiodarone treatment caused a significant decrease (p<0.05) in both the 6beta-OHC/UFC ratio and the 24-hour urinary excretion of 6beta3-OHC. These results suggest that amiodarone is an inhibitor of CYP3A activity.     

High Incidence of Impaired Glucose Regulation in Patients With no Known History of Diabetes Mellitus But With Hyperglycemia After Undergoing a Cardiac Surgical Procedure

ObjectiveTo determine the implications of the presence of hyperglycemia after a cardiac surgical procedure in patients with no history of diabetes mellitus (DM).MethodsWe conducted a prospective study of 50 consecutive patients with no known history of DM who underwent a cardiac surgical procedure and had postoperative hyperglycemia (plasma glucose levels ≥ 110 mg/dL), requiring an insulin drip to achieve tight glucose control. These patients underwent a 2-hour oral glucose tolerance test (OGTT) at 6 weeks postoperatively to determine the percentage of subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or type 2 DM.ResultsOf the 50 patients, 32 (64%) were found to have persistent glucose dysregulation. On the basis of OGTT results, 20% had IFG, 16% had both IFG and IGT, 10% had only IGT, and 18% had type 2 DM. Of the patients with newly diagnosed diabetes, 89% had a 6-week postoperative fasting plasma glucose (FPG) concentration of < 126 mg/dL. There was a significant correlation between the preoperative FPG levels and the 6-week postoperative 2-hour OGTT glucose levels (P < .01). No correlation was found between the 6-week postoperative FPG levels and the 2-hour OGTT glucose levels (P = .26).ConclusionHyperglycemia after a cardiac surgical procedure implies a high risk of persistent glucose dysregulation. Preoperative FPG levels correlated better with 2-hour OGTT results than did the 6-week postoperative FPG values, but both were insensitive markers for diagnosing type 2 DM in these patients. In our cohort, hemoglobin A1c was not predictive of abnormalities of glucose metabolism. Our data support the need for performing a postoperative OGTT in patients with no known history of DM but the presence of hyperglycemia after a cardiac operation. (Endocr Pract. 2009;15:425-430)