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

Experts recommend tumor removal as first-line treatment for Cushing’s syndrome

The Endocrine Society today issued a Clinical Practice Guideline (CPG) on strategies for treating Cushing’s syndrome, a condition caused by overexposure to the hormone cortisol.

The CPG, entitled “Treatment of Cushing’s Syndrome: An Endocrine Society Clinical Practice Guideline,” was published online and will appear in the August 2015 print issue of the Journal of Clinical Endocrinology and Metabolism (JCEM), a publication of the Endocrine Society.

Cushing’s syndrome occurs when a person has excess cortisol in the blood for an extended period, according to the Hormone Health Network. When it is present in normal amounts, cortisol is involved in the body’s response to stress, maintains blood pressure and cardiovascular function, keeps the immune system in check, and converts fat, carbohydrates and proteins into energy. Chronic overexposure to the hormone can contribute to the development of cardiovascular disease, infections and blood clots in veins.

People who take cortisol-like medications such as prednisone to treat inflammatory conditions, including asthma and rheumatoid arthritis, can develop Cushing’s syndrome. The high cortisol levels return to normal when they stop taking the medication. This is called exogenous Cushing’s syndrome.

In other cases, tumors found on the adrenal or pituitary glands or elsewhere in the body cause the overproduction of cortisol and lead to the development of Cushing’s syndrome. The Clinical Practice Guidelines focus on this form of the condition, known as endogenous Cushing’s syndrome.

“People who have active Cushing’s syndrome face a greater risk of death – anywhere from nearly twice as high to nearly five times higher – than the general population,” said Lynnette K. Nieman, MD, of the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, MD, and chair of the task force that authored the guideline. “To reduce the risk of fatal cardiovascular disease, infections or blood clots, it is critical to identify the cause of the Cushing’s syndrome and restore cortisol levels to the normal range.”

In the CPG, the Endocrine Society recommends that the first-line treatment for endogenous Cushing’s syndrome be the removal of the tumor unless surgery is not possible or unlikely to address the excess cortisol. Surgical removal of the tumor is optimal because it leaves intact the hypothalamic-pituitary-adrenal axis, which is integral to the body’s central stress response.

Other recommendations from the CPG include:

  • Tumors should be removed by experienced surgeons in the following situations:— A tumor has formed on one or both of the two adrenal glands.— A tumor that secretes adrenocorticotropic hormone (ACTH) – the hormone that signals the adrenal glands to produce cortisol – has formed somewhere in the body other than the adrenal or pituitary gland.

    — A tumor has formed on the pituitary gland itself.

  • Patients who continue to have high levels of cortisol in the blood after surgery should undergo additional treatment.
  • People who had an ACTH-producing tumor should be screened regularly for the rest of their lives for high cortisol levels to spot recurrences.
  • If patients’ cortisol levels are too low following surgery, they should receive glucocorticoid replacement medications and be educated about adrenal insufficiency, a condition where the adrenal glands produce too little cortisol. This condition often resolves in 1-2 years.
  • Morning cortisol and/or ACTH stimulation tests, or insulin-induced hypoglycemia, can be used to test for the recovery of the hypothalamic-pituitary-adrenal axis in people who have low cortisol levels after surgery. Once the tests results return to normal, glucocorticoid replacement can be stopped.
  • People who have undergone pituitary surgery should be re-evaluated for other pituitary hormone deficiencies during the post-operative period.
  • Patients who have a pituitary tumor and have undergone surgery to remove both adrenal glands should be regularly evaluated for tumor progression using pituitary MRIs and tests for ACTH levels.
  • Radiation therapy may be used to treat a pituitary tumor, especially if it is growing. While awaiting the effect of radiation, which may take months to years, treatment with medication is advised.
  • To assess the effect of radiation therapy, the patient’s cortisol levels should be measured at 6- to 12-month intervals.
  • Medications may be used to control cortisol levels as a second-line treatment after surgery for a pituitary gland tumor, as a primary treatment for ACTH-secreting tumors that have spread to other parts of the body or suspected ACTH-secreting tumors that cannot be detected on scans. Medications also can be used as adjunctive treatment to reduce cortisol levels in people with adrenal cortical carcinoma, a rare condition where a cancerous growth develops in the adrenal gland.
  • People with Cushing’s syndrome should be treated for conditions associated with the disease, such as cardiovascular disease risk factors, osteoporosis and psychiatric symptoms.
  • Patients should be tested for recurrence throughout their lives except in cases where the person had a benign adrenal tumor removed.
  • Patients should undergo urgent treatment within 24 to 72 hours of detecting excess cortisol if life-threatening complications such as serious infection, pulmonary thromboembolism, cardiovascular complications and acute psychosis are present.

More information: The Hormone Health Network offers resources on Cushing’s syndrome at www.hormone.org/questions-and-answers/2012/cushing-syndrome

Cushing’s Syndrome

Prof André Lacroix, MDcorrespondence,  Richard A Feelders, MD, Constantine A Stratakis, MD, Lynnette K Nieman, MD

If One Partner Has Cushing’s Syndrome, Can The Couple Still Get Pregnant?

Cushing’s syndrome can affect fertility in both men and women.

Women

The high levels of cortisol in Cushing’s syndrome disrupt a woman’s ovaries. Her menstrual periods may stop completely or become irregular. As a result, women with Cushing’s syndrome almost always have difficulty becoming pregnant.5,6,7 For those who do become pregnant, the risk of miscarriage is high.5,6,7

In rare cases, usually when a woman’s Cushing’s syndrome is caused by a benign adrenal tumor, pregnancy can occur, but it brings high risk for the mother and fetus.5,6,7

After a woman is treated for Cushing’s syndrome, her ovaries often recover from the effects of too much cortisol. Her regular menstrual cycles will return, and she can become pregnant.8

In some women, regular periods do not return after they are treated for Cushing’s syndrome. This occurs if surgery removes the part of the pituitary gland involved in reproduction.4 An infertility specialist can prescribe hormone therapy to bring back regular periods, ovulation, and fertility.8

Men

A man diagnosed with Cushing’s syndrome may have a decline in sperm production and could have reduced fertility.9 He also might experience a lowered sex drive as well as impotence (pronounced IM-puh-tuhns). In addition, some medications used to treat Cushing’s syndrome can reduce fertility.10 However, fertility usually recovers after Cushing’s syndrome is cured and treatment has stopped.9

Does Cushing’s syndrome affect pregnancy?

Cushing’s syndrome can cause serious and potentially life-threatening effects for the mother and the fetus during pregnancy.11,12 For example, Cushing’s syndrome raises a woman’s risk of developing pregnancy-related high blood pressure (called preeclampsia, pronounced pree-i-KLAMP-see-uh, or eclampsia) and/or pregnancy diabetes, which also is called gestational (pronounced je-STEY-shuhn-ul) diabetes). Infection and slow healing of any wounds are more likely, as is heart failure. When the syndrome is caused by a tumor, it will be surgically removed as early as possible to reduce any threat.13


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  9. Jequier, A.M. Endocrine infertility. In Male infertility: A clinical guide (2nd ed.). Cambridge University Press, 2011: chap 20, pages 187-188. Retrieved May 19, 2012, from http://books.google.com/books?id=DQL0YC79uCMC&pg=PA188&lpg=PA188&dq=male+infertility+causes+and+treatment+Cushing&source=bl&ots=k1Ah5tVJC7&sig=WJR4N0wUawlh0Rant31QMPq6ufs&hl=en&sa=X&ei=hGe5T-LrHYSX6AHgrvmzCw&ved=0CGoQ6AEwAQ#v=onepage&q=male%20infertility%20causes%20and%20treatment%20Cushing&f=false. External Web Site Policy
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From https://www.nichd.nih.gov/health/topics/cushing/conditioninfo/pages/faqs.aspx