Cushing’s: Update on signs, symptoms and biochemical screening

10.1530/EJE-15-0464

  1. Lynnette Nieman

+Author Affiliations


  1. L Nieman, RBMB, NIH, Bethesda, 20817-1109, United States
  1. Correspondence: Lynnette Nieman, Email: niemanl@mail.nih.gov

Abstract

Endogenous pathologic hypercortisolism, or Cushing’s syndrome, is associated with poor quality of life, morbidity and increased mortality. Early diagnosis may mitigate against this natural history of the disorder.

The clinical presentation of Cushing’s syndrome varies, in part related to the extent and duration of cortisol excess. When hypercortisolism is severe, its signs and symptoms are unmistakable. However, most of the signs and symptoms of Cushing’s syndrome are common in the general population (e.g. hypertension and weight gain) and not all are present in every patient.

In addition to classical features of glucocorticoid excess, such as proximal muscle weakness and wide purple striae, patients may present with the associated co-morbidities that are caused by hypercortisolism. These include cardiovascular disease, thromboembolic disease, psychiatric and cognitive deficits, and infections. As a result, internists and generalists must consider Cushing’s syndrome as a cause, and endocrinologists should search for and treat these co-morbidities.

Recommended tests to screen for Cushing’s syndrome include 1 mg dexamethasone suppression, urine free cortisol and late night salivary cortisol. These may be slightly elevated in patients with physiologic hypercortisolism, which should be excluded, along with exogenous glucocorticoid use. Each screening test has caveats and the choice of tests should be individualized based on each patient’s characteristics and lifestyle.

The objective of this review was to update the readership on the clinical and biochemical features of Cushing’s syndrome that are useful when evaluating patients for this diagnosis.

Read the entire manuscript at http://www.eje-online.org/content/early/2015/07/08/EJE-15-0464.full.pdf+html

Urinary free cortisol measurement most accurate first-line test for Cushing’s syndrome diagnosis

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Ceccato F, et al. J Clin Endocrinol Metab. 2015;doi:10.1210/jc.2015-2507.

Measuring 24-hour urinary free cortisol with liquid chromatography-mass spectrometry is the most accurate first-line diagnostic tool for diagnosing Cushing’s syndrome in adults, according to research published in The Journal of Clinical Endocrinology & Metabolism.

Filippo Ceccato, MD, of the University Hospital of Padova, Italy, and colleagues analyzed data from 137 adults from 2012 to 2014 (108 women; mean age, 41 years) with clinical conditions suggestive of hypercortisolism. Within the cohort, 38 had a confirmed diagnosis of Cushing’s syndrome (27 women); 99 did not have the diagnosis. In all patients, researchers measured 24-hour urinary free cortisol with liquid chromatography-tandem mass spectrometry (LC-MS/MS), late-night salivary cortisol with a radio-immunometric method and serum cortisol with a 1-mg dexamethasone suppression test. Researchers performed all three tests on patients within 2 weeks to avoid fluctuations in cortisol production.

Researchers found that using LC-MS/MS to measure urinary free cortisol revealed both a combined higher positive ratio (10.7) and a lower negative likelihood ratio (0.03) among the three first-line tests.

For the 1-mg dexamethasone suppression test, researchers found a cutoff of 138 nmol/L revealed the best specificity (97%), whereas the 50 nmol/L cutoff confirmed the best sensitivity (100%). For the late-night salivary cortisol test, researchers found a cutoff of 14.46 provided a sensitivity of 84% and specificity of 89%. For urinary free cortisol, a cutoff of 170 nmol during 24 hours provided a sensitivity of 97% and specificity of 91%.

After using a receiver operating characteristic (ROC)-contrast analysis to compare the power of each test alone and combined with one another, the urinary free cortisol assay was at least as good as all the other possible combinations, according to researchers.

“This result is rather surprising because some authors have recently advocated replacing [the urinary free cortisol] assay with other tests,” the researchers wrote. “Our findings go against such a hypothesis, probably because we used LC-MS/MS in our routine clinical practice for all patients, meaning that high [urinary free cortisol] concentrations pointed to a high likelihood of [Cushing’s syndrome].”

Researchers also observed higher urinary free cortisol levels in men with Cushing’s syndrome, as well as greater cortisol suppression in the 1-mg dexamethasone suppression test in women, but noted that sex did not affect the diagnostic accuracy of tests.

“Choosing between valid tests for ruling out [Cushing’s syndrome] in high-risk populations requires an understanding of their diagnostic performance in different clinical settings,” the researchers wrote. “We recommend measuring [urinary free cortisol] with LC-MS/MS as the first-line screening test for the diagnosis of [Cushing’s syndrome], and then confirming hypercortisolism with the 1-mg [dexamethasone suppression test] or late-night salivary cortisol assay.” – by Regina Schaffer

Disclosure: The researchers report no relevant financial disclosures.

From http://www.healio.com/endocrinology/adrenal/news/online/%7B1851a57b-4e76-4c5d-ad7e-ef217c2a2336%7D/urinary-free-cortisol-measurement-most-accurate-first-line-test-for-cushings-syndrome-diagnosis

Effects of Cushing’s syndrome on the human brain

Cushing’s syndrome (CS) is characterized by excessive exposure to cortisol, and is associated with both metabolic and behavioural abnormalities even after biochemical cure. Andela et al conducted a systematic review of literature available in the PubMed, Embase, Web of Knowledge, and Cochrane databases evaluating structural and functional changes in the brain identified by magnetic resonance imaging in CS patients. They also reviewed potential associations between brain characteristics and disease status, cognitive functioning, psychopathology, and general well-being.

They found CS has profound effects on the human brain including abnormalities in structural grey matter, possibly white matter and neurochemical and functional alterations. After correction of hypercortisolism, the structural and neurochemical alterations improve substantially and correlate with improvements in clinical and behavioural outcomes. Nevertheless, abnormalities in both grey- and white matter are not completely reversible at long-term remission and are accompanied by psychological symptoms and impairments in cognitive functioning.

The full review by Andela et al. is published in the European Journal of Endocrinology 2015 173DOI:10.1530/EJE-14-1101

From http://www.ese-hormones.org/news/article.aspx?articleid=9306

Bilateral Adrenal Incidentalomas May Have Different Etiology Than Unilateral

MedicalResearch.com Interview with:
Quan-Yang Duh MD
Chief, Section of Endocrine Surgery
UCSF Medical Center

Medical Research: What is the background for this study? What are the main findings?

Dr. Quan-Yang Duh: At UCSF we have a monthly Adrenal Conference (involving surgeons, endocrinologists and radiologists) to discuss patients we are consulted for adrenal tumors. About 30% of these are for incidentally discovered adrenal tumors (versus those found because of specific indications such as clinical suspicion or genetic screening). Of these 15-20% has bilateral adrenal tumors.

The evaluation of unilateral incidentaloma has been very well studied and many national guidelines have been published with specific management recommendations. So during our monthly adrenal conference, we have a routine “script” for evaluation and recommendations (rule out metastasis by looking for primary cancer elsewhere, rule out pheochromocytoma and Cushing, resect secreting tumors or large tumors, and if no operation recommended repeat scan in 6 months, etc.). This “script” has worked very well for patients with unilateral incidentaloma.

However, we were less certain when we made recommendations about bilateral incidentalomas because there was very little literature or guidelines written about it. We had some gut feelings, but we were not sure that we were recommending the right things. We needed more data. That was the main reason for the study.

What we found in our study was that although the possible subclinical diseases were the same – hypercortisolism and pheochromocytoma, the probabilities were different. The patients with bilateral incidentalomas were more likely to have subclinical Cushing’s and less likely to have pheochromocytomas than those with unilateral incidentalomas.

Medical Research: What should clinicians and patients take away from your report?

Dr. Quan-Yang Duh: The work up for bilateral adrenal incidentalomas is similar to that for unilateral incidentalomas. However, patients with bilateral incidentalomas are more likely to have subclinical Cushing’s and less likely to have pheochromocytoma. This difference should be kept in mind when clinicians evaluating these patients.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Quan-Yang Duh: Because our study used data that were from patients who were referred to us to be discussed at our Adrenal Conference, there is likely to be a selection bias (probably higher proportion with clinically significant diseases). It would be interesting to prospectively study ALL patients with adrenal  from a radiology department and see whether our results are confirmed.

Citation:

7 health conditions that are responsible for making you fat

Cushing’s syndrome: Cushing’s syndrome or hypercortisolism is a condition caused when the adrenal glands produce too much cortisol. This leads to a buildup of fat in the face, upper back and abdomen. Cushing’s syndrome can also be a side-effect of certain medications.

Read the other 6 at 7 health conditions that are responsible for making you fat | Read Health Articles & Blogs at TheHealthSite.com.