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/

Bruising easily and gaining weight? Don’t mistake high blood pressure for this syndrome

By Olivia Lerche June 30th, 2017

Cushing’s sydnrome [sic]: Condition can have the same symptoms as high blood pressure

The condition is a hormonal disorder caused by prolonged exposure to the hormone cortisol – which can be caused by taking steroids. Cortisol regulates metabolism and immune response in the body.

Other people develop Cushing’s syndrome because their bodies produce too much cortisol.

It is most common in adults aged between 20 and 50 although women are almost three time [sic] as likely to be diagnosed.

While the condition is rare and only affects around one in every 50,000 people – the syndrome can affect people with type 2 diabetes, obese and have poorly controlled blood sugar levels.

The condition is also more common in people with high blood pressure.

Cushing’s syndrome – also called hypercortisolism – can cause a number of symptoms.These can include:
Weight gain
Thinning skin which can bruise easily
Reddish-purple stretch marks on the arms, legs, breasts, thighs, stomach and buttocks
It can also cause the face to become rounder – causing fat to deposit on the face
Muscle or bone weakness is also a sign of the condition
A loss of libido – decreased interest in sex – is also a symptom

Cushing's sydnrome: Condition can have the same symptoms as high blood pressureGETTY

Cushing’s sydnrome [sic]: Condition has similar symptoms as high blood pressure and metabolic syndrome

However, other symptoms can include excess hair on the face, irregular periods, severe fatigue, high blood pressure, high blood sugar irritability or depression and even a fatty deposit between the shoulders.The National Institute of Diabetes and Digestive and Kidney Diseases said: “Metabolic syndrome – a combination of problems that includes excess weight around the waist, high blood pressure, abnormal levels of cholesterol and triglycerides in the blood, and insulin resistance-also mimics the symptoms of Cushing’s syndrome.”Cushing’s syndrome often develops as a side effect of treatment with corticosteroids.

Corticosteroids are widely used to reduce inflammation and treat autoimmune conditions  – where the immune system malfunctions and attacks healthy tissue – such as rheumatoid arthritis, Crohn’s disease and lupus.

Cushing's sydnrome: Condition can have the same symptoms as high blood pressureGETTY

Cushing’s sydnrome [sic]: Condition can have the same symptoms as high blood pressure

Metabolic syndrome also mimics the symptoms of Cushing’s syndrome

However, the condition can be hard to diagnose because of the similarity to high blood pressure.To diagnose the disease, patients will usually need to have a saliva test, urine test and blood test to measure cortisol levels in the body.To treat the condition, patients will usually have to decrease the levels of steroids they are taking.

However, there are complications if the condition is left untreated.

It can lead to high blood pressure and increase the risk of heart disease and stroke.

Adiponectin level may serve as predictor of subclinical Cushing’s syndrome

Unal AD, et al. Int J Endocrinol. 2016;doi:10.1155/2016/8519362.

 

In adults with adrenal incidentaloma, adiponectin levels may help predict the presence of subclinical Cushing’s disease, according to recent findings.

Asli Dogruk Unal, MD, of the department of endocrinology and metabolism at Memorial Atasehir Hospital in Istanbul, and colleagues analyzed data from 40 patients with adrenal incidentaloma (24 women; mean age, 61 years) and 30 metabolically healthy adults without adrenal adenomas or hyperplasia (22 women; mean age, 26 years). All patients with type 2 diabetes were newly diagnosed and not on any antidiabetic therapies; included patients were not using statin therapy for about 12 weeks.

Participants provided blood samples

Among patients with adrenal incidentaloma, eight (20%) were diagnosed with subclinical Cushing’s syndrome; median adenoma diameter in these patients was 3.05 cm. The remaining patients were classified as nonfunctional adrenal incidentaloma. Compared with patients who had nonfunctional adrenal incidentaloma, patients with subclinical Cushing’s syndrome had a higher median midnight cortisol level (9.15 µg/dL vs. 5.1 µg/dL; P = .004) and urinary free cortisol level (249 µg per 24 hours vs. 170 µg per 24 hours; P = .007).

In two group comparisons, researchers found that only adiponectin level was lower in the subclinical Cushing’s syndrome group vs. the nonfunctional adrenal incidentaloma group (P = .007); there were no observed between-group differences for age, BMI, waist circumference, insulin levels, homeostasis model assessment for insulin resistance (HOMA-IR) or lipid profiles.

Adiponectin level was negatively associated with insulin level, HOMA-IR, triglyceride level and midnight cortisol level, and was positively associated with body fat percentage, HDL and adrenocorticotropic hormone levels. In linear regression analysis, age was found to be an increasing factor, whereas sex, HOMA-IR, LDL, waist circumference and presence of subclinical Cushing’s syndrome were decreasing factors.

In evaluating the receiver operating characteristic analysis, researchers found that adiponectin level had a predictive value in determining the presence of subclinical Cushing’s syndrome (area under the curve: 0.81; 95% CI, 0.67-0.96). Sensitivity and specificity for an adiponectin value of 13 ng/mL or less in predicting the presence of subclinical Cushing’s syndrome were 87.5% and 77.4%, respectively; positive predictive value and negative predictive value were 50% and 96%, respectively.

“Presence of [subclinical Cushing’s syndrome] should be considered in case of an adiponectin level of 13 ng/mL in [adrenal incidentaloma] patients,” the researchers wrote. “Low adiponectin levels in [subclinical Cushing’s syndrome] patients may be important in treatment decision due to the known relation between adiponectin and cardiovascular events. In order to increase the evidences on this subject, further prospective follow-up studies with larger number of subjects are needed.” – by Regina Schaffer

Disclosure: The researchers report no relevant financial disclosures.

From http://www.healio.com/endocrinology/adrenal/news/in-the-journals/%7B81c38f07-b378-4ca1-806b-d5c17bea064c%7D/adiponectin-level-may-serve-as-predictor-of-subclinical-cushings-syndrome

Recurrent sellar mass after resection of pituitary macroadenoma

A Puerto Rican woman aged 50 years presented to an ophthalmologist with complaints of vision changes, including difficulty seeing images in her peripheral vision in both eyes and difficulty in color perception. Her medical history was significant for menopause at age 43 years, type 2 diabetes and hypertension. She had no prior history of thyroid disease, changes in her weight, dizziness or lightheadedness, headaches, galactorrhea or growth of her hands or feet.

Formal visual fields showed bitemporal superior quadrantopsia, and she was sent to the ED for further evaluation.

Imaging and laboratory tests

A pituitary protocol MRI was performed that showed a large 3 cm x 2 cm x 2.2 cm mass in the pituitary with mild osseous remodeling of the sella turcica and mass effect on the optic chiasm (Figure 1). The mass was isointense with the brain parenchyma on T1-weighted and T2-weighted images and homogeneously enhanced after IV gadolinium contrast administration.

Baseline laboratory samples drawn at 11 p.m. in the ED showed a cortisol of 16.9 µg/dL (nighttime reference range: 3-16 µg/dL), adrenocorticotropic hormone 65 pg/mL (reference range: 6-50 pg/mL), prolactin 19.4 ng/mL (reference range: 5.2-26.5 ng/mL), thyroid-stimulating hormone 1.36 µIU/mL (reference range: 0.35-4.9 µIU/mL), free thyroxine 0.9 ng/dL (reference range: 0.6-1.8 ng/dL), triiodothyronine 85 ng/dL (reference range: 83-160 ng/dL), follicle-stimulating hormone (FSH) 11.1 mIU/mL (postmenopausal reference range: 26.7- 133.4 mIU/mL) and luteinizing hormone (LH) 1.2 mIU/mL (postmenopausal reference range: 5.2-62 mIU/mL).

 

Figure 1. T1-weighted MRI images with and without contrast of the pituitary. Coronal (A) and sagittal (C) images showed a large isodense (with brain parenchyma) 3 cm x 2 cm x 2.2 cm mass (red arrow) in the sella with superior extension to the optic chiasm. After gadolinium contrast, coronal (B) and sagittal (D) images show the mass homogenously enhances consistent with a pituitary adenoma.

Images courtesy of Pavani Srimatkandada, MD.

Given the patient’s high nighttime cortisol and adrenocorticotropic hormone (ACTH) levels, she underwent an overnight dexamethasone suppression test with 1 mg dexamethasone. Her morning cortisol was appropriately suppressed to less than 1 µg/dL, excluding Cushing’s disease.

Pituitary adenoma resection

The patient was diagnosed with a nonsecreting pituitary adenoma with suprasellar extension and optic chiasm compression with visual field deficits. The macroadenoma caused an inappropriately normal LH and FSH in a postmenopausal woman consistent with hypogonadotrophic hypogonadism.

She underwent transnasal transsphenoidal resection of the nonsecreting pituitary adenoma. The dural defect caused by the surgery was patched with an abdominal fat graft with a DuraSeal dura patch. A postoperative MRI showed complete resection of the adenoma with no evaluable tumor in the sella (Figure 2). Her postoperative course was complicated by transient diabetes insipidus requiring intermittent desmopressin; however, this resolved before her discharge from the hospital.

Figure 2. T1-weighted MRI images with contrast. Coronal views before (A) and after (B) transphenoidal tumor resection show complete resolution of the enhancing pituitary mass (A; red arrow) that is replaced with a new hypodense mass in the sella (B; yellow arrow). This mass is filled with cerebrospinal fluid with a residual rim of enhancing tissue. This is consistent with the development of a pseudomeningocele in the sella.

 

Postoperative testing confirmed secondary deficiency of the adrenal, thyroid and ovarian axes requiring hormone therapy. The patient had stable temporal hemianopia in the left eye with improved vision in the right eye.

Recurrent mass detected

One year after surgery, during a routine follow-up appointment, the patient reported no dizziness, lightheadedness, worsening vision changes, rhinorrhea or headache. She had a follow-up MRI of the brain with and without contrast, which showed the interval appearance of a mass in the sella that extended from the sphenoid sinus into the sella and came in contact with the optic nerve (Figure 3).

Figure 3. Axial MRI images of the sella after resection of pituitary adenoma. On T1-weighted images the mass (red arrow) in the sella is hypodense (black) compared with the brain parenchyma. On T2-weighted images, the mass (red arrow) is hyperdense (bright) compared with the brain, consistent with fluid. Cerebrospinal fluid in the sulci on the brain surface and the vitreous fluid within the eye are also hyperintense on T2-weighted images (yellow arrows).

 

On MRI, the mass was isodense with the cerebral spinal fluid (CSF) with a residual rim of enhancing normal pituitary tissue. This appearance is consistent with the postoperative development of a pseudomeningocele and not a solid mass in the sella (Table).

Pseudomeningoceles are abnormal collections of CSF that communicate with the CSF space around the brain; these occur after brain surgery involving duraplasty (incision and repair of the dura). Unlike meningoceles, pseudomeningoceles are not completely encased by a surrounding membrane, and they communicate with the circulating CSF. Similar to CSF, a pseudomeningocele is hypodense (dark) compared with brain on T1-weighted MRI images and hyperdense (bright) on T2-weight images.

 

Pseudomeningocele treatment

Treatment may be conservative or may involve neurosurgical repair if symptomatic. Little published data addresses the development of pseudomeningoceles after transsphenoidal pituitary surgery, but this complication occasionally occurs, especially if the dural incision is large. One study noted that pseudomeningoceles are one of the most common complications after suboccipital decompression for Chiari’s malformation, but the effect of this complication is unclear.

Endocrinologists must recognize that recurrent development of pituitary masses after transsphenoidal pituitary adenoma surgery may not represent regrowth of pituitary tissue, but instead development of a meningocele/pseudomeningocele. Pseudomeningocele can be easily confirmed because this fluid collection has very different MRI characteristics than pituitary adenoma (Table). Given that patients may remain asymptomatic after the development of a pseudomeningocele, periodic MRI imaging, hormonal evaluation and ophthalmologic monitoring of visual fields are required after transsphenoidal pituitary surgery.

References:
  • Hernandez Guilabert PM. Poster No C-1330. Presented at: European Society of Radiology; March 7-11, 2013; Vienna.
  • Parker SL, et al. J Neurosurg. 2013;doi:10.3171/2013.8.JNS122106.
For more information:
  • Stephanie L. Lee, MD, PhD, ECNU, is an associate professor of medicine and associate chief, in the Section of Endocrinology, Diabetes and Nutrition at Boston Medical Center. Lee can be reached at Boston Medical Center, 88 E. Newton St., Endocrinology Evans 201, Boston, MA 02118; email: stephanie.lee@bmc.org. Lee reports no relevant financial disclosures.
  • Pavani Srimatkandada, MD, is an endocrinology fellow in the Section of Endocrinology, Diabetes and Nutrition at Boston Medical Center. Srimatkandada can be reached at Boston Medical Center, 88 E. Newton St., Endocrinology Evans 201, Boston, MA 02118. She reports no relevant financial disclosures.

From http://www.healio.com/endocrinology/thyroid/news/print/endocrine-today/%7B82430fb6-bbe4-4908-a389-447eee8cd005%7D/recurrent-sellar-mass-after-resection-of-pituitary-macroadenoma

Screening for Cushing’s syndrome: Is it worthwhile?

The data suggests that Cushing is not frequent enough to support the use of routine screening in patients with morbid obesity and type 2 DM. Also only 1 % of hypertensive patients have secondary hypertension due to CS. However, screening should be considered in young patients with resistant DM and/or hypertension. Among patients with osteoporosis and vertebral fractures up to 5 % were diagnosed with subclinical hypercortisolism; most of these had adrenal adenoma. Screening for CS is important in subjects with adrenal incidentaloma, and many studies show a high prevalence (~10 %) of Cushing or subclinical CS in these patients.

Abstract

Introduction

Cushing’s syndrome (CS) is a rare disease characterized by a collection of signs and symptoms, also common in the general population without elevated cortisol secretion. During the last years more patients with CS are identified earlier and with milder disease. Many of these patients are diagnosed during screening efforts performed for certain or isolated complaints like weight gain, diabetes mellitus (DM), hypertension, osteoporosis, elevated white blood cell counts and more.

Methods

In this review article the most popular screening test performed in the studies cited was the 1-mg dexamethasone suppression test.

Conclusions

Cushing is not frequent enough to support the use of routine screening in patients with morbid obesity and type 2 DM. Also only 1 % of hypertensive patients have secondary hypertension due to CS. However, screening should be considered in young patients with resistant DM and/or hypertension. Among patients with osteoporosis and vertebral fractures up to 5 % were diagnosed with subclinical hypercortisolism; most of these had adrenal adenoma. Screening for CS is important in subjects with adrenal incidentaloma, and many studies show a high prevalence (~10 %) of Cushing or subclinical CS in these patients.

Buy this article for $39.00 at http://link.springer.com/article/10.1007%2Fs11102-015-0634-9

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