The Challenge of Obesity in Diagnosing Cushing’s Syndrome and Strategies to Improve Methods

The effects of obesity on the diagnosis of Cushing’s syndrome and strategies to alter the traditional approaches have been addressed in a new review study.

The study, “Diagnosis and Differential Diagnosis of Cushing’s Syndrome,” appeared in The New England Journal of Medicine. The author was Dr. Lynn D. Loriaux, MD and PhD, and a professor of medicine at the Division of Endocrinology, Diabetes and Clinical Nutrition at the School of Medicine, Oregon Health & Science University (OHSU), in Portland, Oregon.

Traditionally, exams of patients with glucocorticoid excess focused on the presence of changes in anabolism (the chemical synthesis of molecules). Given the increase in obesity in the general population, changes in anabolism can no longer distinguish Cushing’s syndrome from metabolic syndrome.

However, analyses of anti-anabolic changes of cortisol – including osteopenia (lower bone density), thin skin, and ecchymoses (injury that causes subcutaneous bleeding) – are an effective way to make this distinction.

The worldwide prevalence of metabolic syndrome in obese people is estimated at about 10%. Conversely, the incidence of undiagnosed Cushing’s syndrome is about 75 cases per 1 million people.

Cushing’s and metabolic syndrome share significant clinical similarities, including obesity, hypertension, and type 2 diabetes. Therefore, “making the diagnosis is the least certain aspect in the care of patients with [Cushing’s],” Loriaux wrote.

Regarding a physical examination, patients with osteoporosis, reduced skin thickness in the middle finger, and three or more ecchymoses larger than 1 cm in diameter and not associated with trauma are more likely to have Cushing’s. Researchers estimate the probability of people with all three of these symptoms having Cushing’s syndrome is 95%.

Measuring 24-hour urinary-free cortisol levels allows the assessment of excess glucocorticoid effects, typical of Cushing’s syndrome. The test, which should be done with the most stringent techniques available, averages the augmented secretion of cortisol in the morning and the diminished secretion in the afternoon and at night.

Dexamethasone suppression is one of the currently used screening tests for Cushing’s syndrome. Patients with obesity and depression should not show decreased plasma cortisol levels when dexamethasone is suppressed. However, given its low estimated predictive value (the proportion of positive results that are “true positives”), “this test should not influence what the physician does next and should no longer be used” to screen for Cushing’s, the author wrote.

Some patients may show evidence of Cushing’s syndrome at a physical examination, but low urinary free cortisol excretion. This may be due to glucocorticoids being administered to the patient. In this case, the glucocorticoid must be identified and discontinued. Periodic Cushing’s assessments that measure urinary free cortisol should be performed.

The opposite can also occur: no clinical symptoms of Cushing’s, but elevated urinary free cortisol excretion and detectable plasma levels of the hormone corticotropin. In these patients, the source of corticotropin secretion, which can be a tumor or the syndrome of generalized glucocorticoid resistance, must be determined.

The disease process can be corticotropin-dependent or independent, depending on whether the hormone is detectable. Corticotropin in Cushing’s syndrome can come from the pituitary gland (eutopic) or elsewhere in the body (ectopic).

Loriaux recommends that the source of corticotropin secretion be determined before considering surgery. Up to 40% of patients with pituitary adenomas have nonfunctioning tumors (the tumor does not produce any hormones) and the corticotropin source is elsewhere. If misdiagnosed, patients will likely undergo an unnecessary surgery, with a mortality rate of 1%.

Patients with an ectopic source of corticotropin should undergo imaging studies in the chest, followed by abdominal and pelvic organs. If these tests fail to detect the source, patients should undergo either the blockade of cortisol synthesis or an adrenalectomy (removal of adrenal glands).

However, corticotropin-independent Cushing’s is usually caused by a benign adrenal tumor that uniquely secretes cortisol.

“Such tumors can be treated successfully with laparoscopic adrenalectomy,” Loriaux wrote. If the tumor secretes more than one hormone, it is likely malignant. Surgical to remove the tumor and any detectable metastases should be conducted.

Overall, “the treatment for all causes of [Cushing’s syndrome], other than exogenous glucocorticoids, is surgical, and neurosurgeons, endocrine surgeons, and cancer surgeons are needed,” Loriaux wrote in the study.

“This level of multidisciplinary medical expertise is usually found only at academic medical centers. Thus, most, if not all, patients with [Cushing’s syndrome] should be referred to such a center for treatment.”

From https://cushingsdiseasenews.com/2017/10/24/diagnosing-cushings-syndrome-amid-challenge-of-obesity-and-strategies-to-improve-methods/

Ectopic Cushing’s syndrome associated with thoracic tumors

Results of a retrospective review conducted in southern India demonstrate that ectopic Cushing’s syndrome occurred most commonly in association with thoracic tumors.

Researchers added that early control over hypercortisolemia was necessary to prevent metabolic complications and infections, both of which had the potential to be life-threatening.

“As compared to patients with pituitary-dependent Cushing’s syndrome, patients with [ectopic Cushing Syndrome] present with a rapid progression of symptoms,” Nihal Thomas, MD, MNAMS, DNB, FRACP, professor in the department of endocrinology, diabetes and metabolism at Christian Medical College, Vellore, India, and colleagues wrote. “It is also associated with typical features of proximal muscle weakness, severe hypokalaemic metabolic alkalosis, hyperpigmentation, edema, hypertension and glucose intolerance. Early diagnosis and localization of the ectopic source of [adrenocorticotrophic hormone] is crucial, because the treatment of choice in most of these patients is complete excision of the tumor. Localizing the source of excess ACTH continues to be a challenge in most patients.”

Thomas and colleagues reviewed the records of 21 patients treated at a tertiary care center in southern India from 2006 to 2015. The researchers documented patients’ clinical features, history and images from radiological findings and PET scans, as well as details of management, follow-up and outcomes. They also compared those with ectopic Cushing’s syndrome with 20 patients who had Cushing’s disease.

Median age was 34 years. Thomas and colleagues reported that one patient demonstrated “an occult source of ACTH.” The rest had a variety of tumors: bronchial carcinoid (n = 7), thymic carcinoid (n = 7), lung malignancies (n = 3), medullary thyroid carcinoma (n = 2) and pancreatic neuroendocrine tumor (n = 1).

At presentation, muscle weakness was the most common clinical feature (95%), followed by hyperpigmentation (90%), facial puffiness (76%), easy bruising (61%), edema (57%) and striae (52%). Slightly less than half (43%) showed extensive acne. Central obesity in ectopic Cushing’s syndrome was uncommon and occurred in 14% of patients (n = 3), according to Thomas and colleagues; however, it was more prevalent (n = 18) in those with Cushing’s disease.

Median cortisol at 8 a.m. was 55.5 mcg/dL, the researchers wrote, while median 8 a.m. ACTH was 207 pg/mL. The median 24-hour urinary free cortisol level was 2,484 mcg.

Compared with patients with Cushing’s disease, those with ectopic Cushing’s syndrome had “markedly higher” midnight cortisol and ACTH, as well as basal cortisol and ACTH.

During follow-up, more than half of patients (12 of 21) with ectopic Cushing’s syndrome developed life-threatening infections. Although nine patients received surgery for their tumors, only one patient achieved a complete cure during the study period, the researchers wrote.

“In our series, patients with [ectopic Cushing’s syndrome] have more profound hypokalemia, and hypercortisolemia with higher levels of ACTH,” Thomas and colleagues wrote. “The prognosis of patients with [ectopic Cushing’s syndrome] was dependent on tumor histology. The role of a timely adrenalectomy needs to be considered in patients with hypercortisolemia unresponsive to medical management, and in patients with metastatic or recurrent disease.” – by Andy Polhamus

Disclosure: Endocrine Today was unable to confirm any relevant financial disclosures.

From https://www.healio.com/endocrinology/adrenal/news/in-the-journals/%7Be42c81a5-fd5b-4313-9b2b-9bcbdec7f8ce%7D/ectopic-cushings-syndrome-associated-with-thoracic-tumors

Scalp Hair Cortisol Accurate in Cushing’s Syndrome Diagnosis

Scalp hair cortisol measurement is an accurate first-line diagnostic test for Cushing’s syndrome in adults and offers several advantages over other first-line diagnostic procedures, according to findings published in the European Journal of Endocrinology.

“[Hair cortisol content] has practical advantages over currently used diagnostic tests, since sample collection can easily be performed in an outpatient setting and is not dependent on patient adherence to sampling instructions,” Elisabeth F. C. van Rossum, MD, PhD, professor at Erasmus MC, University Medical Center Rotterdam in the Netherlands, and colleagues wrote. “Furthermore, [hair cortisol content] measurement offers retrospective information about cortisol levels over months of time in a single measurement, thereby potentially circumventing the limitations posed by the variability in cortisol secretion in endogenous [Cushing’s syndrome].”

Van Rossum and colleagues analyzed data from 43 patients with confirmed endogenous Cushing’s syndrome and 35 patients with suspected Cushing’s syndrome in whom diagnosis was excluded after testing (patient controls), all evaluated between 2009 and 2016 at an endocrinology outpatient clinic at Erasmus MC. Adults from a previously published validation study served as healthy controls (n = 174). Researchers measured scalp hair samples, 24-hour urinary free cortisol, serum cortisol and salivary cortisol, and used Pearson’s correlation to determine associations between hair cortisol content and first-line screening tests for Cushing’s syndrome.

Hair cortisol content was highest in patients with Cushing’s syndrome (geometric mean, 106.9 pg/mg; 95% CI, 77.1-147.9) and higher compared with both healthy controls (mean, 8.4 pg/mg; 95% CI, 7-10) and patient controls (mean, 12.7 pg/mg; 95% CI, 8.6-18.6). Using healthy controls as the reference population, researchers found that the optimal cutoff for diagnosis of Cushing’s syndrome via hair cortisol content was 31.1 pg/mg; sensitivity and specificity were 93% and 90%, respectively (area under the curve = 0.958). Results were similar when using patient controls as the reference population, according to the researchers.

Hair cortisol content was correlated with urinary free cortisol (P < .001), serum cortisol (P < .001) and late-night salivary cortisol (P < .001). In addition, in two patients with ectopic Cushing’s syndrome, researchers observed a gradual rise in hair cortisol content in the 3 to 6 months before disease diagnosis.

“Together with a straightforward sample collection procedure, this method may prove to be a convenient noninvasive screening test for [Cushing’s syndrome],” the researchers wrote. “Additionally, our results indicate that hair cortisol measurements provide clinicians a tool to retrospectively assess cortisol secretion in patients with [Cushing’s syndrome], months to years back in time. This also offers the opportunity to estimate the onset of hypercortisolism and thus the duration of the disease before diagnosis.” – by Regina Schaffer

Disclosure: The researchers report no relevant financial disclosures.

From http://www.healio.com/endocrinology/adrenal/news/in-the-journals/%7B72da0183-e1a8-48cb-a1fd-332c7999beb5%7D/scalp-hair-cortisol-accurate-in-cushings-syndrome-diagnosis

Ectopic adrenocorticotropic hormone syndrome caused by neuroendocrine tumors of the thymus

Background and purpose: Thymic neuroendocrine carcinomas (TNECs) are extremely uncommon. Certain cases of TNECs can produce the adrenocorticotropic hormone (ACTH) and cause ectopic ACTH syndrome (EAS). The current literature on this topic consists mainly of case reports, and therapeutic guidelines are lacking. The aim of this study was to discuss the diagnosis, surgical management, and prognosis of EAS caused by TNECs to improve clinical experience with this rare disease.

Methods: From June 1984 to June 2014, at the Peking Union Medical College Hospital, the surgical interventions and follow-up outcomes of 16 consecutive patients (eight men and eight women) with EAS caused by TNECs were retrospectively analyzed.

Results: The median age was 32.5 years (range: 13–47 years), and the median disease duration was 8.5 months (range: 1–150 months). All patients presented with clinical and biochemical evidence indicating a diagnosis of Cushing’s syndrome.

Contrast-enhanced thoracic computed tomography scans were critical to locating the ACTH-producing tumor and evaluating the feasibility of resection. All patients underwent surgery. One patient died of septicemia in the intensive care unit 2 weeks after surgery. No other morbidity or mortality occurred during the perioperative period. The median overall survival (OS) was 41 months (95% CI: 30.3–51.7 months), and the progression-free survival was 28 months (95% CI: 21.6–34.3 months). Both overall survival (P=0.002) and progression-free survival (P=0.030) improved significantly after complete resection.

Conclusion: TNEC is an extremely aggressive disease that should be considered when treating patients with Cushing’s syndrome due to ectopic ACTH secretion. In particular, all suspected patients should undergo contrast-enhanced thoracic computed tomography scans to facilitate early diagnosis. The current first-line treatment is surgical resection, and complete resection is a favorable prognostic factor. However, additional patients and a longer follow-up will be needed to determine the variables that are predictive of survival and to improve patient prognosis.

Download this article at https://www.dovepress.com/ectopic-adrenocorticotropic-hormone-syndrome-caused-by-neuroendocrine–peer-reviewed-article-OTT

Metopirone effective treatment for hypercortisolemia in Cushing’s syndrome

Hypercortisolemia in Cushing’s syndrome can be controlled with Metopirone therapy, according to recent study findings published in The Journal of Clinical Endocrinology & Metabolism.

John Newell-Price, PhD, FRCP, of the University of Sheffield in the United Kingdom, and colleagues evaluated 195 patients with Cushing’s syndrome to determine the effect of Metopirone (metyrapone, HRA Pharma) on the control of excess cortisol. Cushing’s syndrome was most commonly Cushing’s disease (n = 115), followed by ectopic adrenocorticotropic hormone (ACTH; n = 37), benign adrenal disease (n = 30), adrenocortical carcinoma (n = 10), ACTH-independent macronodular adrenal hyperplasia (n = 2) and primary pigmented nodular adrenal hyperplasia (n = 1).

The biochemical parameters of activity of Cushing’s syndrome were measured by mean serum cortisol day-curve (target, 150-300 nmol/L), early morning serum cortisol and 24-hour urinary free cortisol.

Most participants received monotherapy (n = 164) and had significant improvements in excess cortisol during treatment. Significant improvements were revealed from first to last review for cortisol day-curve, early morning cortisol and 24-hour urinary free cortisol.

At last review, 55% of participants who had cortisol day-curve, 43% who had urinary free cortisol, 46% who had early morning cortisol less than 331 nmol/L and 76% who had early morning cortisol less than the upper limit of normal/600 nmol/L achieved control.

The median final dose of metyrapone was 1,375 mg among those with Cushing’s disease, 1,500 mg among those with ectopic ACTH, 750 mg among those with benign adrenal disease and 1,250 among those with adrenocortical carcinoma.

Twenty-five percent of participants experienced adverse events, with the most common being mild gastrointestinal upset and dizziness. Most of the adverse events occurred within 2 weeks of initiation or dose increase and were reversible.

“Overall more than 80% of patients showed an improvement in levels of circulating cortisol with over 50% achieving biochemical eucortisolemia when on monotherapy when assessed by the stringent criterion of control on a [cortisol day-curve],” the researchers wrote. “It is likely that additional therapies were added because of the severity of disease and clinician preference, but the retrospective and multicenter nature of our study precludes a formal assessment of this. Furthermore, our data support that metyrapone monotherapy is an effective treatment for hypercortisolemia either before or after surgical intervention to the primary cause of [Cushing’s syndrome].” – by Amber Cox

Disclosure: Newell-Price reports various financial ties with HRA Pharma and Novartis. Please see the full study for a list of all other authors’ relevant financial disclosures.

From http://www.healio.com/endocrinology/adrenal/news/online/%7B067ff9a2-dbce-428f-be94-849e1f466150%7D/metopirone-effective-treatment-for-hypercortisolemia-in-cushings-syndrome

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