Causes of Cushing’s Syndrome

Cushing’s syndrome—also referred to as hypercortisolism—is fairly rare. However, researchers have boiled down a few key causes of Cushing’s syndrome, which you’ll read about below.

The cause of Cushing’s syndrome boils down to: Your body is exposed to too much cortisol. There are a few ways that this over-exposure can happen, including taking certain medications and having a tumor on your pituitary gland or adrenal gland.

Can Taking Corticosteroids Cause Cushing’s Disease?
One particular type of medication can cause Cushing’s syndrome: corticosteroids. But rest assured: Not all steroid medications cause Cushing’s syndrome. It’s more common to develop Cushing’s syndrome from steroids you take in pill form or steroids you inject. Steroid creams and steroids you inhale are not common causes of Cushing’s syndrome.

Some steroid medications have the same effect as the hormone cortisol does when produced in your body. But as with an excessive production of cortisol in your body, taking too much corticosteroid medications can, over time, lead to Cushing’s syndrome.

It’s common for people with asthma, rheumatoid arthritis, and lupus to take corticosteroids. Prednisone (eg, Deltasone) is an example of a corticosteroid medication.

Other Cushing’s Disease Causes
Your body can over-produce cortisol or adrenocorticotropic hormone (ACTH). The pituitary gland secretes ACTH, which is in charge of stimulating the adrenal glands to produce cortisol, and the adrenal glands are responsible for releasing cortisol into the bloodstream.

Cortisol performs important tasks in your body, such as helping to maintain blood pressure and regulate how your body metabolizes proteins, fats, and carbohydrates, so it’s necessary for your body to maintain normal levels of it.

The following can cause excessive production of cortisol or ACTH, leading to Cushing’s syndrome.

  • Pituitary gland tumors: A benign (non-cancerous) tumor of the pituitary gland can secrete an excess amount of ACTH, which can cause Cushing’s syndrome. Also known as pituitary adenomas, benign tumors of the pituitary gland affect women 5 times more often than men.
  • Adrenal gland tumors: A tumor in one of your adrenal glands can lead to Cushing’s syndrome by causing too much cortisol to enter your bloodstream. Most of these tumors are non-cancerous (called adrenal adenomas).

    Cancerous adrenal tumors—called adrenocortical carcinomas—are relatively rare. These types of tumors typically cause extremely high levels of cortisol and very rapid development of symptoms.

  • Other tumors in the body: Certain tumors that develop outside the pituitary gland can also produce ACTH. When this happens, it’s known as ectopic ACTH syndrome. Ectopic means that something is in an abnormal place or position. In this case, only the pituitary gland should produce ACTH, so if there is a tumor producing ACTH and it isn’t located on the pituitary, it’s ectopic.

    It’s unusual to have a tumor that secretes ACTH outside the pituitary. These tumors are usually found in the pancreas, lungs, or thyroid, and they can be benign or malignant (cancerous).

    The most common forms of ACTH-producing tumors are small cell lung cancer, which accounts for about 13% of all lung cancer cases, and carcinoid tumors—small, slow-growing tumors that arise from hormone-producing cells in various parts of the body.

  • Familial Cushing’s syndrome: Although it’s rare, Cushing’s syndrome can develop from an inherited tendency to have tumors on one or more of your endocrine glands. Some inherited conditions, such as multiple endocrine neoplasia (MEN 1), can involve tumors that over-produce cortisol or ACTH, leading to Cushing’s syndrome.

If you think you could have Cushing’s syndrome or you have questions about the causes of Cushing’s syndrome, talk to your doctor immediately.

Written by | Reviewed by Daniel J. Toft MD, PhD, adapted from  http://www.endocrineweb.com/conditions/cushings-syndrome/cushings-syndrome-causes

Midnight Salivary Cortisol Versus Urinary Free and Midnight Serum Cortisol as Screening Tests for Cushing’s Syndrome

From PubMed

Gafni RI, Papanicolaou DA, Nieman LK.
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892-1862, USA.

OBJECTIVE: There is currently no optimal test to screen for endogenous Cushing’s syndrome (CS) in children. Traditional 24-hour urine or midnight serum cortisol values may be difficult to obtain or elevated by venipuncture stress. We hypothesized that salivary cortisol measurement is a reliable way to screen for CS in children.

STUDY DESIGN: Sixty-seven children (5-17 years) were studied: 24 obese volunteers, 29 non-obese volunteers, and 14 children with CS. Saliva was obtained at 7:30 AM, bedtime, and midnight for measurement of free cortisol by radioimmunoassay.

RESULTS: Salivary cortisol was detectable in all morning and evening samples from patients with CS but was frequently undetectable in healthy children at bedtime (66%) and at midnight (90%). With cut points that excluded healthy children, a midnight salivary cortisol value of 7.5 nmol/L (0.27 microg/dL) identified 13 of 14 patients with CS, whereas a bedtime value >27.6 nmol/L (1 microg/dL) detected CS in 5 of 6 patients. The diagnostic accuracies of midnight salivary cortisol and urinary free cortisol per square meter were the same (93%).

CONCLUSION: Salivary cortisol measurement at bedtime or midnight rules out CS in nearly all cases. Nighttime salivary cortisol sampling is thus a simple, accurate way to screen for hypercortisolism in children. PMID: 10891818 [PubMed – indexed for MEDLINE]


THE PRINCIPLE RESEARCHER FOR SALIVARY CORTISOLS IS HERSHEL RAFF AT THE UNIVERSITY OF WISCONSIN. HE IS A RESEARCH SCIENTIST, NOT A DOCTOR. YOU CAN CONTACT HIM DIRECTLY FOR ORDERING INFO.

Salivary Cortisol: A Screening Technique

By: Dr. Hershel Raff

Cushing’s syndrome – endogenous hypercortisolism – is characterized by a loss of circadian rhythmicity. In normal patients, cortisol levels peak in the early morning hours and decrease to substantially lower levels at night. Rather than the normal decrease in late evening cortisol, patients with Cushing’s syndrome of any cause fail to decrease cortisol secretion in the late evening. Therefore, the measurement of elevated late evening cortisol is helpful in the diagnosis of Cushing’s syndrome. Obtaining a late night, unstressed plasma cortisol is virtually impossible in most clinical practices. Salivary cortisol is in equilibrium with the free, biologically active portion of cortisol in the plasma. Therefore, if one obtains a saliva sample in patients at bedtime in their homes under unstressed conditions, one can make the diagnosis of endogenous hypercortisolism.

A simple way to sample saliva is by using a Salivette made by the Sarstedt Company (Newton, NC). This device consists of a cotton tube and plastic tubes. The patient only has to chew the cotton tube for 2-3 minutes and place it in the plastic tube. The tube is then transported to our lab for analysis.

Late-evening salivary cortisol is not intended to replace the current standard screening test – measurement of a 24 hr urine free cortisol. However, the salivary cortisol test can be extremely useful for patients suspected of having intermittent Cushing’s syndrome. Due to the convenience of sample collection, the patient can sample saliva several evenings in a row. In fact, our clinical endocrinologists routinely order 2-3 consecutive late-evening salivary cortisol samples.


Our research (Raff H, Raff JL, Findling JW. 1998 LATE-NIGHT SALIVARY CORTISOL AS A SCREENING TEST FOR CUSHING’S SYNDROME. J Clin Endocrinol Metab. 83:2681-2686) has shown that the combination of late-evening salivary cortisol and urine free cortisol is very accurate in diagnosing Cushing’s syndrome in most patients. Doctors can obtain a kit by contacting ACL Client Services at 1-800-877-7016.

Editor’s Note: DR. HERSHEL RAFF, PH.D. IS A PROFESSOR OF MEDICINE AND PHYSIOLOGY AT THE MEDICAL COLLEGE OF WISCONSIN’S ENDOCRINE RESEARCH LABORATORY AT ST. LUKE’S MEDICAL CENTER IN MILWAUKEE, WISCONSIN.

Cushing’s Syndrome and Skin Problems

By Afsaneh Khetrapal, BSc (Hons)

Cushing’s Syndrome (sometimes called hypercortisolism) is a hormonal disease caused by an abnormally high level of the hormone cortisol in the body. This may arise because of an endogenous or exogenous source of cortisol. Endogenous causes include the elevated production of cortisol by the adrenal glands, while exogenous causes include the excessive use of cortisol or other similar steroid (glucocorticoid) hormones over a prolonged period of time.

The adrenal glands are situated just above each kidney, and form part of the endocrine system. They have numerous functions such as the production of hormones called catecholamines, which includes epinephrine and norepinephrine. Interestingly, the outer layer (cortex) of the adrenal glands has the distinct responsibility of producing cortisol. This hormone is best known for its crucial role in the bodily response to stress.

At physiologically appropriate levels, cortisol is vital in maintaining normal sleep-wake cycles, and acts to increase blood sugar levels. It suppresses the immune system, regulates the effect of insulin on the metabolism of fats, proteins, and carbohydrates, and help with the homeostasis of water in the body.

Exogenous corticosteroids can also lead to Cushing’s syndrome, when they are used as a form of long-term treatment for various medical conditions. In fact, the long-term use of steroid medication is the most common reason for the development of Cushing’s syndrome.

Prednisolone is the most commonly prescribed steroid medicine. It belongs to a class of medicine that is sometimes used to treat conditions such as certain forms of arthritis and cancer. Other uses include the rapid and effective reduction of inflammation in conditions such as asthma and multiple sclerosis (MS), as well as the treatment of autoimmune conditions such as lupus erythematosus, and rheumatoid arthritis.

Overall, Cushing’s syndrome is quite uncommon and affects approximately 1 in 50,000 people. Most of them are adults between the ages of 20 and 50.  Women are 3 times more commonly affected than men. Additionally, patients who are obese, or those who have type 2 diabetes with poorly controlled blood sugar and blood pressure show a greater predisposition to the disorder.

Symptoms of Cushing’s syndrome

There are numerous symptoms associated with Cushing’s syndrome, which range from muscle weakness, hypertension, curvature of the spine (kyphosis), osteoporosis, and depression, to fatigue Specific symptoms which pertain to the skin are as follows:

  • Thinning of the skin and other mucous membranes: the skin becomes dry and bruises easily. Cortisol causes the breakdown of some dermal proteins along with the weakening of small blood vessels. In fact, the skin may become so weak as to develop a shiny, paper-thin quality which allows it to be torn easily.
  • Increased susceptibility of skin to infections
  • Poor wound healing  of bruises, cuts, and scratches
  • Spots appear on the upper body, that is, on the face, chest or shoulders
  • Darkened skin which is seen on the neck
  • Wide, red-purple streaks (at least half an inch wide) called striae which are most common on the sides of the torso, the lower abdomen, thighs, buttocks, arms, and breasts, or in areas of weight gain. The accumulation of fat caused by Cushing’s syndrome stretches the skin which is already thin and weakened due to cortisol action, causing it to hemorrhage and stretch permanently, healing by fibrosis.
  • Acne: this can develop in patients of all ages.
  • Swollen ankles: this is caused by the accumulation of fluid, called edema.
  • Hyperhidrosis (excessive sweating)

Reviewed by Dr Liji Thomas, MD

From http://www.news-medical.net/health/Cushings-Syndrome-and-Skin-Problems.aspx

Who’s at Risk for Cushing’s?

by Kristen Monaco
Contributing Writer, MedPage Today

Researchers have developed a new method to assess specific populations for Cushing’s syndrome, based on results from a multicenter study.

The prospective cohort study evaluated at-risk patients for Cushing’s syndrome to create a novel type of scoring system in order to better predict the development of disease, stated lead author Antonio León-Justel, PhD,of the Seville Institute of Biomedicine in Spain, and colleagues.

Cushing’s syndrome is identified by an excess of cortisol and/or glucocorticoids in the blood, which can result in myriad negative health outcomes, including an increased risk of death and morbidity, according to the study in The Journal of Clinical Endocrinology & Metabolism.

Because Cushing’s syndrome (CS) is complex and difficult to diagnose, there is a necessity for new methods to assess at-risk populations in order to mitigate the rising prevalence of the disorder, the authors noted.

“The diagnosis of CS might pose a considerable challenge even for experienced endocrinologists since there are no pathognomonic symptoms or signs of CS and most of the symptoms and signs of CS are common in the general population including obesity, hypertension, bone loss, and diabetes,” the senior author, Alfonso Leal Cerro, MD, toldMedPage Today via email. “Routine screening for CS remains impractical due to the estimated low prevalence of the disease. However this prevalence might be higher in at-risk populations.”

The authors screened a total of 353 at-risk patients from 13 different hospitals across Spain between January 2012 and July 2013 to measure cortisol variability from saliva samples.

At-risk populations, which the authors note have a higher prevalence of Cushing’s syndrome, included individuals with type 2 diabetes, hypertension, and osteoporosis.

The patients screened in the study were each identified as having at least two of the risk factors for Cushing’s syndrome: high blood pressure (defined as taking two or more drugs and having a systolic blood pressure over 140 mmHg and/or a diastolic blood pressure over 90 mmHg), obesity (body mass index >30), uncontrolled diabetes (HbA1c>7.0%), osteoporosis (T-score ≥ -2.5 SD), and virilization syndrome (hirsutism) with menstrual disorders.

The researchers used clinical and biochemical methods of assessment. Clinical methods included inspection of physical characteristics, such as muscle atrophy, purple striae, and/or facial plethora. Biochemical methods included collecting saliva and blood samples from participants to test cortisol levels using a chemiluminescence method. Each individual was identified as either negative for hypercortisolism (late-night salivary cortisol [LNSC] ≤ 7.5 nmol/L and dexamethasone suppression test [DST] ≤ 50 nmol/L) or positive for hypercortisolism (LNSC > 7.5 nmol/L and DST > 50 nmol/L).

Univariate testing indicated the following significant characteristics to be positively correlated with the development of Cushing’s syndrome:

  • Muscular atrophy (15.2, CI 95% 4.48-51.25);
  • Osteoporosis (4.60, 1.66-12.75); and
  • Dorsocervical fat pad (3.32, 1.48-7.5).

A logistic regression analysis of LNSC values also showed significant correlation between Cushing’s syndrome and the following top three characteristics:

  • Muscular atrophy (9.04, CI 95% 2.36-34.65);
  • Osteoporosis (3.62, CI 95% 1.16-11.35); and
  • Dorsocervical fat pad (3.3, CI 95% 1.52-7.17).

Roberto Salvatori, MD, professor and medical director of the Johns Hopkins Pituitary Center, who was not involved with the study, commented to MedPage Today in an email: “Any endocrinologist would proceed with careful Cushing biochemical evaluation in the presence of the clinical features (muscular atrophy, osteoporosis, and dorsocervical fat pad) that are well known to be associated with hypercortisolism. Of notice, the odds ratio is further increased by an abnormal late-night salivary cortisol, which is already a screening test for hypercortisolism.”

The researchers used their results to develop an equation to determine the level of risk a patient has for developing Cushing’s syndrome, taking into account factors for osteoporosis, dorsocervical fat pads, muscular atrophy, and LNSC levels.

Although the study was able to develop a comprehensive risk model for the syndrome, when tested against the prevalence for Cushing’s syndrome in the subject group, the equation generated a total of 56 false-positive and 25 true-positive results. Overall, the researchers wrote, 83% of patients were accurately classified as belonging to the at-risk population when using the equation.

Because the newly developed equation for identifying at-risk individuals involved factors that are relatively easy to test for, the authors noted that clinical application is broad and cost-effective in a primary care setting.

“We would like to test the scoring system in different clinical settings such as primary care or hypertension clinics,” Leal Cerro said. “Primary care would be a particularly interesting setting since it might significantly decrease the time to diagnosis, something critical to avoid an excessive exposure to glucocorticoid excess and consequent deleterious effects.”

Salvatori said that while the study was a good start at shedding light on some of the unknowns about Cushing’s syndrome, more research is required. “The real question in my mind is when does a non-endocrinologist need to suspect Cushing in a general medicine, orthopedic, or other clinic? When the internal medicine residents ask me about guidelines for ‘who to screen for hypercortisolism in my clinic,’ I am unable to provide an evidence-based answer.”

The study was funded by a grant from Novartis Oncology, Spain.

León-Justel and Leal Cerro disclosed financial relationships with Novartis Oncology, Spain.

  • Reviewed by F. Perry Wilson, MD, MSCEAssistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner

LAST UPDATED 08.15.2016

Screening tool accurately predicts Cushing’s syndrome in most at-risk patients

León-Justel A, et al. J Clin Endocrinol Metab. 2016;doi:10.1210/jc.2016-1673.

A scoring system based on clinical signs and a late-night salivary cortisol test accurately predicted Cushing’s syndrome in at-risk patients, with only one missed case, according to recent findings.

In a prospective, multicenter study, Antonio León-Justel, PhD, of the biochemistry department at the Hospital Universitario Virgen del Rocío in Seville, Spain, and colleagues analyzed data from 353 patients treated in endocrinology units in 13 university hospitals in Spain between 2012 and July 2013. All participants had at least two of five features compatible with Cushing’s syndrome, including obesity, hypertension, poorly controlled diabetes,hirsutism with menstrual disorders and osteoporosis; none of the included patients was referred to clinic with the suspicion of Cushing’s syndrome. All patients underwent late-night salivary cortisol and serum cortisol measurements after a low-dose (1 mg) dexamethasone test; those with discordant results were followed until December 2014 (mean follow-up time, 22.2 months).

Within the cohort, 26 (7.4%) patients were diagnosed with Cushing’s syndrome (20 adrenocorticotropic hormone-dependent; six of adrenal origin). In univariate logistic regression analysis, researchers found that muscular atrophy (OR = 15.2), followed by osteoporosis (OR = 4.6), dorsocervical fat pad (OR = 3.32), absence of obesity (OR = 0.21) and absence of type 2 diabetes (OR = 0.26), were associated with Cushing’s syndrome; late-night salivary cortisol values were also related (OR = 1.26). However, after multivariable adjustment, researchers found that muscular atrophy (OR = 9.04; 95% CI, 2.36-34.65), osteoporosis (OR = 3.62; 95% CI, 1.16-11.35) and dorsocervical fat (OR = 3.3; 95% CI, 1.52-7.17) remained as independent variables with Cushing’s syndrome.

“Obesity and type 2 diabetes displayed a negative association with [Cushing’s syndrome],” the researchers wrote. “These results might seem paradoxical a priori, but we want to stress that in our analyzed cohort, the prevalence of obesity and diabetes was exceedingly high (likely reflecting the reasons for referral to endocrinology units).”

In receiver operating characteristic (ROC) analysis, researchers determined that a cutoff value of 9.17 nmol/L for late-night salivary cortisol provided the best results, with an area under the curve of 0.893 (P < .001), a sensitivity of 88.5% and specificity of 83.2%.

Researchers developed a risk-scoring system, determining cutoff values from a ROC curve. The estimated area under the ROC curve was 0.93 (P < .001), with a sensitivity of 96.2% and specificity of 82.9%.

“Selecting this cutoff value of four, 271 of 327 subjects (83%) without [Cushing’s syndrome] were correctly identified, while only 1 of 26 [Cushing’s syndrome] cases was missed,” the researchers wrote. “Our model yielded 56 false positives.

“Although all the assessments were performed by specialists (endocrinologists) in our study, this scoring system could be easily tested in independent cohorts and different settings such as primary care or hypertension clinics,” the researchers wrote. “At the very least, our diagnostic prediction model could be used as a framework for future studies and potential improvements in diagnostic performance.” – by Regina Schaffer

Disclosure: Leon-Justel and another researcher report receiving a research grant from Novartis Oncology, Spain.

From http://www.healio.com/endocrinology/adrenal/news/in-the-journals/%7B50d3d398-c8fe-41e9-b815-87626bfe8a4b%7D/screening-tool-accurately-predicts-cushings-syndrome-in-most-at-risk-patients