Cushing Patients Could Be Diagnosed, Subtyped Using Plasma Steroid Levels

Patients with different subtypes of Cushing’s syndrome (CS) have distinct plasma steroid profiles. This could be used as a test for diagnosis and classification, a German study says.

The study, “Plasma Steroid Metabolome for Diagnosis and Subtyping Patients with Cushing Syndrome,” appeared in the journal Clinical Chemistry.

A quick diagnosis of CS is crucial so that doctors can promptly give therapy. However, diagnosing CS is often complicated by the multiple tests necessary not just to diagnose the disease but also to determine its particular subtype.

Cortisol, which leads to CS when produced at high levels, is a steroid hormone. But while earlier studies were conducted to determine whether patients with different subtypes of CS had distinct steroid profiles, the methods researchers used were cumbersome and have been discontinued for routine use.

Recently, a technique called LC-MS/MS has emerged for multi-steroid profiling in patients with adrenocortical dysfunction such as congenital adrenal hyperplasia, adrenal insufficiency and primary aldosteronism.

Researchers at Germany’s Technische Universität in Dresden used that method to determine whether patients with the three main subtypes of CS (pituitary, ectopic and adrenal) showed differences in plasma steroid profiles. They measured levels of 15 steroids produced by the adrenal glands in single plasma samples collected from 84 patients with confirmed CS and 227 age-matched controls.

They found that CS patients saw huge increases in the plasma steroid levels of 11-deoxycortisol (289%), 21-deoxycortisol (150%), 11-deoxycorticosterone (133%), corticosterone (124%) and cortisol (122%), compared to patients without the disease.

Patients with the ectopic subtype had the biggest jumps in levels of these steroids. However, plasma 18-oxocortisol levels were particularly low in ectopic disease. Other steroids demonstrated considerable variation.

Patients with the adrenal subtype had the lowest concentration of dehydroepiandrosterone (DHEA) and DHEA-SO4, which are androgens. Patients with the ectopic and pituitary subtype had the lowest concentration of aldosterone.

Through the use of 10 selected steroids, patients with different subtypes of CS could be identified almost as closely as with other tests, including the salivary and urinary free cortisol test, the dexamethasone-suppressed cortisol test, and plasma adrenocorticotropin levels. The misclassification rate using steroid levels was 9.5 percent, compared to 5.8 percent in other tests.

“This study using simultaneous LC-MS/MS measurements of 15 adrenal steroids in plasma establishes distinct steroid metabolome profiles that might be useful as a test for CS,” the team concluded, adding that using LC-MS/MS is advantageous, as specimen preparation is simple and the entire panel takes 12 minutes to run. This means it could be offered as a single test for both identification and subtype classification.

From https://cushingsdiseasenews.com/2018/01/02/plasma-steroid-levels-used-screen-diagnosis-subtyping-patients-cushing-syndrome/

2 Health Conditions That Can Cause Hyperpigmentation

Addison’s disease: Hyperpigmentation is a classic symptom of Addison’s disease, an endocrine disorder in which the adrenal glands fails to produce steroid hormone. The disease causes darkening of the skin in certain areas.

Cushing’s syndrome: The abnormal amount of cortisol in the human body causes a condition known as the Cushing’s syndrome. And one of the symptoms of the disorder is hyperpigmentation of the skin.

Adapted from http://www.thehealthsite.com/diseases-conditions/health-conditions-that-can-cause-hyperpigmentation/

Patients Undergoing Adrenalectomy Should Receive Steroid Substitutive Therapy

All patients who undergo removal of one adrenal gland due to Cushing’s syndrome (CS) or adrenal incidentaloma (AI, adrenal tumors discovered incidentally) should receive a steroid substitutive therapy, a new study shows.

The study, “Predictability of hypoadrenalism occurrence and duration after adrenalectomy for ACTH‐independent hypercortisolism,” was published in the Journal of Endocrinological Investigation.

CS is a rare disease, but subclinical hypercortisolism, an asymptomatic condition characterized by mild cortisol excess, has a much higher prevalence. In fact, subclinical hypercortisolism, is present in up to 20 percent of patients with AI.

The hypothalamic-pituitary-adrenal axis (HPA axis) is composed of the hypothalamus, which releases corticotropin-releasing hormone (CRH) that acts on the pituitary to release adrenocorticotropic hormone (ACTH), that in turn acts on the adrenal gland to release cortisol.

To avoid excess cortisol production, high cortisol levels tell the hypothalamus and the pituitary to stop producing CRH and ACTH, respectively. Therefore, as CS and AI are characterized by high levels of cortisol, there is suppression of the HPA axis.

As the adrenal gland is responsible for the production of cortisol, patients might need steroid substitutive therapy after surgical removal of AI. Indeed, because of HPA axis suppression, some patients have low cortisol levels after such surgeries – clinically known as post-surgical hypocortisolism (PSH), which can be damaging to the patient.

While some researchers suggest that steroid replacement therapy should be given only to some patients, others recommend it should be given to all who undergo adrenalectomy (surgical removal of the adrenal gland).

Some studies have shown that the severity of hypercortisolism, as well as the degree of HPA axis suppression and treatment with ketoconazole pre-surgery in CS patients, are associated with a longer duration of PSH.

Until now, however, there have been only a few studies to guide in predicting the occurrence and duration of PSH. Therefore, researchers conducted a study to determine whether HPA axis activity, determined by levels of ACTH and cortisol, could predict the occurrence and duration of PSH in patients who undergo an adrenalectomy.

Researchers studied 80 patients who underwent adrenalectomy for either CS or AI. Prior to the surgery, researchers measured levels of ACTH, urinary free cortisol (UFC), and serum cortisol after 1 mg dexamethasone suppression test (1 mg-DST).

After the surgery, all patients were placed on steroid replacement therapy and PSH was determined after two months. For those with PSH, levels of cortisol were determined every six months for at least four years.

Results showed that PSH occurred in 82.4 percent of CS patients and 46 percent of AI patients. PSH lasted for longer than 18 months in 50 percent of CS and 30 percent of AI patients. Furthermore, it lasted longer than 36 months for 35.7 percent of CS patients.

In all patients, PSH was predicted by pre-surgery cortisol levels after the 1 mg-DST, but with less than 70 percent accuracy.

In AI patients, a shorter-than-12-month duration of PSH was not predicted by any HPA parameter, but was significantly predicted by an absence of pre-surgery diagnosis of subclinical hypercortisolism.

So, this study did not find any parameters that could significantly predict with high sensitivity and specificity the development or duration of PSH in all patients undergoing adrenalectomy.

Consequently, the authors concluded that “the PSH occurrence and its duration are hardly predictable before surgery. All patients undergoing unilateral adrenalectomy should receive a steroid substitutive therapy.”

From https://cushingsdiseasenews.com/2017/12/08/therapy-cushings-patients-adrenalectomy/

Desmopressin is Promising Alternative in Diagnosing Cushing’s Disease

Bilateral inferior petrosal sinus sampling (IPSS) — a procedure that uses desmopressin to determine levels of ACTH hormone from veins that drain from the pituitary gland, is a sensitive way to diagnose patients with Cushing’s disease and find tumors, a Chinese study shows.

The study, “Tumour Lateralization in Cushing’s disease by Inferior Petrosal Sinus Sampling with desmopressin,” appeared in the journal Clinical Endocrinology.

Cushing’s disease is characterized by excessive production of the adrenocorticotropin hormone (ACTH) caused by a tumor in the pituitary gland. ACTH is the hormone that causes the adrenal glands to produce cortisol.

Currently, pituitary imaging is insufficient to confirm a Cushing’s diagnosis. This is because 70 percent of pituitary adenomas in Cushing’s are microadenomas, which are physically very small. As a result, 40 percent of Cushing’s patients are reported as being healthy.

This means that a Cushing’s diagnosis requires a combination of techniques including clinical symptoms, imaging methods and endocrinological assays that include measures of serum cortisol and ACTH levels.

IPSS determines ACTH levels from veins that drain from the pituitary gland. ACTH levels are then compared to ACTH levels in blood. Higher levels in the pituitary gland indicate a pituitary tumor.

IPSS can also be used to determine tumor lateralization, which refers to which side of the pituitary gland the tumor is located on. The test is 69 percent accurate.

Doctors administer IPSS along with corticotropin-releasing hormone (CRH) stimulation. IPSS with CRH is considered the gold standard for preoperative diagnosis of Cushing’s, with a diagnostic sensitivity (or true positive rate) of 95 percent and specificity (or true negative rate) of 90 to 95 percent. Unfortunately, the high cost and limited availability of CRH make it impractical for many patients.

Desmopressin has been used to replace CRH to stimulate ACTH secretion for IPSS, and prior studies have shown that desmopressin’s sensitivity is comparable to that of CRH.

Researchers at Peking Union Medical College in Beijing conducted a retrospective analysis of their experience using desmopressin-stimulated IPSS to determine its diagnostic value for Cushing’s and its predictive value for tumor lateralization.

Researchers analyzed 91 Cushing’s patients who either had negative findings on the MRI imaging of the pituitary or negative high-dose dexamethasone suppression tests, which is another method of evaluation. All patients underwent IPSS with desmopressin, followed by pituitary surgery to extract the tumor.

Of the 91 patients tested, 90 patients had confirmed Cushing’s. And of these, 89 had positive IPSS findings, which led to a sensitivity of 98.9 percent for this test. One patient out of 91 who did not have Cushing’s also underwent this test, which led to a negative IPSS result and a specificity of 100 percent.

Researchers also determined tumor lateralization in patients who were ultimately diagnosed with Cushing’s and underwent surgery. Results of the IPSS showed a 72.5 percent concordance between the results from the IPSS and the surgery.

Therefore, IPSS with desmopressin is a comparable approach to IPSS with CRH for the diagnosis of Cushing’s. It also demonstrates moderate accuracy in determining the location of tumors.

“Like many medical centers in China, we currently have no supply of CRH, while desmopressin is readily available,” researchers concluded. “Moreover, desmopressin is cheaper than CRH. As our data and other studies indicate, IPSS with desmopressin yielded comparable outcomes to IPSS with CRH. Therefore, desmopressin-stimulated IPSS might serve as a possible alternative to CRH-stimulated IPSS.”

From https://cushingsdiseasenews.com/2017/11/14/ipss-desmopressin-alternative-method-diagnosis-cushings-disease/

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/

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