Low Immediate Postoperative Serum-Cortisol Nadir Predicts The Short-Term, But Not Long-Term, Remission After Pituitary Surgery For Cushing’s Disease

Cushing’s disease is an ACTH-producing pituitary adenoma, and the primary treatment is microscopic or endoscopic transsphenoidal selective adenectomy. The aims of the present study were to evaluate whether the early postoperative S-cortisol level can serve as a prognostic marker for short- and long-term remission, and retrospectively review our own short and long term results after surgery for Cushing’s disease.

Methods: This single centre, retrospective study consists of 19 consecutive patients with Cushing’s disease who underwent transsphenoidal surgery.

S-cortisol was measured every 6 h after the operation without any glucocorticoid replacement. We have follow-up on all patients, with a mean follow-up of 68 months.

Results: At the three-month follow-up, 16 patients (84 %) were in remission; at 12 months, 18 (95 %) were in remission and at the final follow-up (mean 68 months), 13 (68 %) were in remission.

Five-years recurrence rate was 26 %. The mean postoperative S-cortisol nadir was significantly lower in the group of patients in remission than in the non-remission group at 3 months, but there was no difference between those in long-term remission compared to those in long-term non-remission.

The optimal cut-off value for classifying 3-month remission was 74 nmol/l.

Conclusion: We achieved a 95 % 1-year remission rate with transsphenoidal surgery for Cushing’s disease in this series of consecutive patients. However, the 5-year recurrence rate was 26 %, showing the need for regular clinical and biochemical controls in this patient group.

The mean postoperative serum-cortisol nadir was significantly lower in patients in remission at 3 months compared to patients not in remission at 3 months, but a low postoperative S-cortisol did not predict long-term remission.

Author: Jon Ramm-Pettersen Helene Halvorsen Johan EvangPål Rønning Per Hol Jens Bollers levJon Berg-Johnsen Eirik Helseth
Credits/Source: BMC Endocrine Disorders 2015, 15:62

Published on: 2015-10-26

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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

The New Molecular Landscape of Cushing’s Disease

Silviu Sbiera#Timo Deutschbein#Isabel Weigand, Martin Reincke, Martin FassnachtcorrespondenceBruno Allolio
#These authors contributed equally to this work.
A few days after acceptance of this manuscript, Bruno Allolio passed away.

Cushing’s disease (CD) is caused by corticotropin-secreting pituitary adenomas and results in substantial morbidity and mortality. Its molecular basis has remained poorly understood until the past few years, when several proteins and genes [such as testicular orphan nuclear receptor 4 (TR4) and heat shock protein 90 (HSP90)] were found to play key roles in the disease. Most recently, mutations in the gene of ubiquitin-specific peptidase 8 (USP8) increasing its deubiquination activity were discovered in a high percentage of corticotroph adenomas. Here, we will discuss emerging insights in the molecular alterations that finally result in CD. The therapeutic potential of these findings needs to be carefully evaluated in the near future, hopefully resulting in new treatment options for this devastating disorder.

Trends

Transsphenoidal surgery and radiotherapy are the treatment of choice in CD. However, despite high initial remission rates, a significant percentage of patients relapse.

Owing to the poor understanding of the pathophysiology of CD, drug therapy is still limited and often only ameliorates the clinical manifestations through blocking of ACTH release or adrenal cortisol synthesis.

Recent research has identified several important proteins (e.g., EGFR, HSP90, TR4, and AVPR1b) whose deregulation is associated with CD and may therefore represent potential therapeutic targets.

Frequent, novel mutations in the USP8 gene that are associated with corticotroph pituitary adenomas were recently discovered that result in reduced EGFR degradation and increased POMC activation in vitro.

Keywords:

Cushing’s disease, pituitary, gene expression, epidermal growth factor receptor, ubiquitin-specific peptidase 8, 14-3-3 proteins

The entire article is available by subscription only.  More information here.

Does a Normal Urine Free Cortisol Result Rule out Cushing’s Syndrome?

Endocrine Society’s 97th Annual Meeting and Expo, March 5–8, 2015 – San Diego
SAT-384:
Does a Normal Urine Free Cortisol Result Rule out Cushing’s Syndrome?
1 and 2

  • 1Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
  • 2National Institutes of Health, Bethesda, MD
Presentation Number: SAT-384
Date of Presentation: March 7, 2015
Abstract:Background: Urine free cortisol (UFC) has been traditionally used as one of the first steps in the diagnostic evaluation of Cushing’s syndrome (CS) (1). False positive results, especially values less than twice the upper limit of normal (ULN), can be seen in uncontrolled diabetes, obesity, depression, alcoholism, increased fluid intake, overcollection and stress. False negative results have also been reported with incomplete collection, in mild or cyclic CS and in patients with renal insufficiency (2-3). We evaluated the diagnostic accuracy of UFC and 24-hour urine 17-hydroxycorticosteroids (17OHCS) in patients with CS.Methods: Retrospective study of all CS patients evaluated at the National Institutes of Health (NIH) from 2009 to 2014. Screening tests used for CS included UFC, 17OHCS, late night salivary cortisol (LNSC), midnight serum cortisol and low dose (1mg overnight or 2-day 2mg/day) dexamethasone suppression test (DST). Values above reference range for UFC, 17OHCS and LNSC, a midnight serum cortisol ≥ 7.5 mcg/dL, and post-dexamethasone cortisol values ≥ 1.8 mcg/dL were considered abnormal. Hourly 24-hour sampling for cortisol was performed in a few cases with a mild clinical phenotype and equivocal test results. UFC was measured using liquid chromatography/tandem mass spectrometry (LC-MS/MS). 17OHCS was measured using colorimetric methodology with Porter-Silber reaction (reported as mg/g of creatinine). Mean of the first two UFC and 17OHCS values (appropriate collection by urine volume and creatinine) obtained within 30 days of initial NIH presentation were used for the purpose of this study.

Results: Seventy-two patients were diagnosed with CS (aged 18-77 years, 51 females). Of these, 51 had Cushing’s disease (CD), 10 had ectopic CS while 2 had an adrenal source of Cushing’s based on pathology. Biochemical tests including inferior petrosal sinus sampling (IPSS) suggested ectopic CS but no tumor was found (occult) in 6 patients. IPSS was indicative of a pituitary source in 2 patients with failed transsphenoidal surgery while one patient did not complete evaluation for ACTH-dependent CS. UFC results were available in all, 17OHCS in 70, LNSC in 21, midnight serum cortisol in 68 and DST results in 37 patients. UFC was falsely normal in six and only minimally elevated (< 2 x ULN) in 13 patients (normal renal function, no history of cyclicity, all had CD). Of these 19 patients, 24h 17OHCS was abnormal in all, LNSC was abnormal in 12, midnight serum cortisol was abnormal in 18 and DST was abnormal in 12 patients. Hourly 24-hour sampling for cortisol performed in 3 of these patients revealed abnormal nadir (> 7.5 mcg/dL) and mean daily serum cortisol (> 9 mcg/dL) levels.

Conclusion: UFC can be falsely normal or only minimally elevated in mild CS. Multiple collections and use of complimentary screening tests including 24-hour urine 17OHCS and LNSC can help make a diagnosis and prevent delay in treatment.

(1) Newell-Price J, et al. Cushing’s syndrome. Lancet. 2006;367(9522):1605-17.  (2) Alexandraki KI, et al. Is urinary free cortisol of value in the diagnosis of Cushing’s syndrome. Curr Opin Endocrinol Diabetes Obes. 2011;18:259–63.  (3) Kidambi S, et al. Limitations of nocturnal salivary cortisol and urine free cortisol in the diagnosis of mild Cushing’s syndrome. Eur J Endocrinol. 2007;157(6):725-31

Nothing to Disclose: STS, LKN

Sources of Research Support: This research was in part supported by the intramural research program of NICHD/NIH

Read the entire article at http://press.endocrine.org/doi/abs/10.1210/endo-meetings.2015.ahpaa.9.sat-384

A Single Midnight Serum Cortisol Measurement Distinguishes Cushing’s Syndrome from Pseudo-Cushing States

Address all correspondence and requests for reprints to: Dimitris A. Papanicolaou, M.D., Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Building 10, Room 10N262, 10 Center Drive, MSC 1862, Bethesda, Maryland 20892-1862. E-mail: papanicd@cc1.nichd.nih.gov.
Received: October 22, 1997
Accepted: January 05, 1998
First Published Online: July 01, 2013

Cushing’s syndrome (CS) may be difficult to distinguish from pseudo-Cushing states (PCS) based on physical findings or urinary glucocorticoid excretion. As the lack of diurnal variation in serum cortisol is characteristic of CS, we studied whether diurnal cortisol determinations could discriminate CS from PCS. Two hundred and sixty-three patients were evaluated: 240 had CS, and 23 had PCS. Urine was collected for 24 h for measurement of cortisol and 17-hydroxycorticosteroids (17OHCS). Blood was drawn at 2300, 2330, 0000, 0030, and 0100 h and at 0600, 0630, 0700, 0730, and 0800 h the next morning for serum cortisol determination. The main outcome measure was the sensitivity of these parameters for the diagnosis of CS at 100% specificity. A midnight cortisol value greater than 7.5 μg/dL correctly identified 225 of 234 patients with CS and all PCS patients. This sensitivity (96%) was superior to that obtained for any other measure, including urinary cortisol (45%), 17OHCS (22%), any other individual cortisol time point (10–92%), the morning (23%) or the evening (93%) cortisol mean, and the ratio (11%) of morning to evening values. We conclude that at 100% specificity, a single serum cortisol value above 7.5 μg/dL at midnight discriminates CS from PCS with higher sensitivity than 24-h urinary cortisol or 17OHCS, or other individual or combined measures of serum cortisol.

OVERPRODUCTION of cortisol is the biochemical hallmark of Cushing’s syndrome (CS) regardless of its etiology and is evidenced by increased urinary cortisol excretion, and a decrease in the circadian variation of serum cortisol (1).

Pseudo-Cushing states (PCS), as the name implies, share many of the features of Cushing’s syndrome, including cortisol overproduction. The hypercortisolism of PCS is hypothesized to be caused by increased activity of the CRH neuron, which, in turn, stimulates ACTH production and release (2). PCS are a heterogeneous group of disorders, including chronic alcoholism and alcohol withdrawal syndrome (3, 4), major depression (5), poorly controlled diabetes mellitus (6, 7), and obesity (8). Additionally, transient hypercortisolism may be associated with less obvious psychiatric conditions (e.g. anxiety) in patients with clinical features reminiscent of CS, such as obesity and hypertension, which are common in the general population. The substantial overlap in urinary free cortisol (UFC) excretion and clinical features between some patients with CS and those with PCS can make it difficult to distinguish between the two conditions (9). Thus, although persistent elevation of 24-h UFC in the presence of unequivocal signs of CS (particularly classic moon facies, prominent centripetal obesity, severe proximal muscle weakness, and violaceous striae) suggest the diagnosis of CS, patients with less obvious signs pose a diagnostic dilemma.

Several tests have been proposed to diagnose CS, including 24-h UFC measurements, the 1-mg overnight dexamethasone suppression test (DST) (10), the 2-day DST (1), and the dexamethasone-CRH (Dex-CRH) stimulation test (8). Each has drawbacks. Twenty-four-hour urinary collections are inconvenient and often incomplete. The 1-mg overnight DST is commonly used as a screening test to exclude the diagnosis of CS. This test has two caveats. First, a criterion for the level of serum cortisol suppression to exclude CS has not been developed using modern RIAs. Second, although the test has a false negative rate of only 2%, it has a significant false positive rate, especially in chronically ill (23%) or obese patients (13%) (11) and in patients with major depression (43%) or other psychiatric disorders (8–41%) (12). Even in normal individuals, the test may be consistent with CS in up to 30% (9).

Similarly, the 2-mg 2-day DST, often used as a confirmatory diagnostic test, has a diagnostic accuracy of only 71% (8). An additional problem is the variable metabolic clearance of dexamethasone (13), which is especially problematic in patients receiving medications that induce the cytochrome P450-related enzymes (e.g.phenytoin, rifampin, and phenobarbital) (14) or in patients with renal or hepatic failure. In such cases, neither DST gives reliable results. Finally, the drawbacks of 24-h urine collections apply to the DST as well.

We previously determined that the dexamethasone-CRH test has a diagnostic accuracy of 98% in the distinction of CS from PCS (8, 15). However, although accurate, this test has the drawbacks related to dexamethasone clearance, as discussed above.

Physiological cortisol secretion is characterized by circadian rhythmicity. Serum cortisol concentration reaches its zenith in the morning (0600–0800 h) and its nadir in the night during the first half of normal sleep. Krieger et al. defined the normal circadian rhythm of plasma corticosteroid levels as the pattern where all plasma glucocorticoid levels from 1600–2400 h were 75% or less of the 0800 h value (16). As previous studies have found that obese individuals retain a normal circadian cortisol rhythm (17), we hypothesized that differences in circadian plasma cortisol values would distinguish CS from PCS. To test this hypothesis, we prospectively measured serum cortisol values during the normal nadir and zenith periods in patients being evaluated for CS.

Read the entire study at http://press.endocrine.org/doi/10.1210/jcem.83.4.4733?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed