Measuring TSH Levels Could Improve Diagnosis for Cushing’s Syndrome

Measuring the variation in thyroid stimulating hormone blood levels between midnight and morning may be better for diagnosing Cushing’s syndrome than current approaches, a study suggests. 

The study, “TSH ratio as a novel diagnostic method for Cushing’s syndrome,” was published in the Endocrine Journal

Cushing’s syndrome (CS) is a condition characterized by excess cortisol in the blood, which can lead to a variety of issues, including obesity, high blood pressure, abnormal lipid levels, osteoporosis, depression, and cognitive impairments.

In some cases, patients have high cortisol levels, but lack the typical physical features of Cushing’s syndrome. These patients are considered to have subclinical Cushing’s syndrome (SCS), and are at higher risk for cardiovascular disease.

Being able to properly diagnose CS and SCS is of utmost importance for proper intervention and treatment of these patients.

Current methods of diagnosis rely on dexamethasone suppressing tests or late-night salivary and blood cortisol tests, as well as measurements of cortisol in urine. However, because cortisol is a stress-hormone, it can be elevated in cases of mental or physical stress, leading to false positive results on these tests. 

Researchers in this study examined if another hormone, called the thyroid stimulating hormone (TSH), could be used to diagnose Cushing’s syndrome with better accuracy.

TSH is a hormone that stimulates the thyroid gland and whose secretion is affected by the body’s circadian rhythm. Its highest levels in the blood are usually seen in the late evening or early morning. However, patients with CS or SCS lack this nocturnal increase in TSH levels, which could be useful as a new diagnostic approach.

The study recruited 142 patients with suspected CS and SCS, and 21 patients with depression, being treated at the Osaka University Hospital in Japan.

Patients received the ordinal screening tests for Cushing’s syndrome, along with measurements of their midnight-to-morning TSH levels.

After taking the tests, only 20 patients were diagnosed as having Cushing’s, including 12 with over (normal) Cushing’s syndrome and 10 with subclinical Cushing’s syndrome.

Patients with Cushing’s had significantly lower midnight TSH levels than non-Cushing’s patients. No differences were seen in morning levels between the groups. Of note, TSH ratio was maintained in patients with depression, suggesting TSH levels could be used to diagnose Cushing’s in patients with depression.

Researchers observed that serum TSH ratio had powerful diagnostic accuracy. Among patients identified as having Cushing’s, 90% actually had the disease. And among patients excluded for Cushing’s, 95% did not have the condition. These sensitivity and specificity rates were better than with current diagnostic approaches.

However, when considering this test, patients with a severe TSH deficiency must be taken into account.

Overall, these results suggest that the midnight-to-morning serum TSH ratio is a potential new way to diagnose both CS and SCS with a higher specificity than the current diagnostic methods

“The strength of our current survey is its prospective design and the evaluation of not only overt CS but also SCS. The limitation is the relatively small number of CS group patients, especially overt CD,” the researchers wrote.

“New prospective studies will be needed with a larger number of patients in order to further clarify the optimal TSH ratio in the diagnosis of CS,” the study concluded. 

From https://cushingsdiseasenews.com/2018/06/28/measuring-tsh-levels-may-improve-cushings-syndrome-diagnosis-study/

Tumors in Cushing’s Patients Have Distinct Genetic Profiles

A study examining the genes expressed in pituitary tumors of Cushing’s disease patients found that these tumors may be grouped into three distinct subsets.

The finding suggests that different biological processes contribute to the development of each subset, an insight that may aid in developing targeted therapies.

The study, “Gene expression profiling in human corticotrope tumors reveals distinct, neuroendocrine profiles,” was published in the Journal of Neuroendocrinology.

In Cushing disease, a pituitary tumor producing excess amounts of the adenocorticotropic hormone causes the body to produce too much cortisol.

Pituitary tumors respond differently to modulators of ACTH secretion, and patients have different disease manifestations, but what makes them differ from one another is unknown.

To determine if the genetic profile of tumors could explain the clinical diversity reported in these patients, Italian researchers evaluated 40 benign, ACTH-secreting pituitary tumors removed from patients with Cushing’s disease.

Of the 20,815 genes examined in the study, 1,259 were significantly elevated in the pituitary tumors. These were mostly involved in pathways that kept the neuroendocrine cell profile.

Based on their genetic profile, researchers were able to cluster tumors into three distinct subgroups. Samples in group A had four specific genes, associated with tumor-related processes, that were overly active. In group B, there were 313 overly active genes, involved in many of the mechanisms of hormone-secreting adenomas.

Group C had 29 highly active genes, all involved in calcium influx and cell growth – mechanisms that are important for the development of ACTH-secreting adenomas.

“It appears that these tumors present a neuroendocrine cell profile but, at the same time, clearly distinct gene expression patterns [are seen] in individual subgroups,” the researchers wrote.

Looking at clinical characteristics that correlated with each subgroup, the researchers found that most group A patients  had macroadenomas (large tumors) that had invaded the sella – the compartment where the pituitary gland resides at the base of the brain. These patients were also older than those in the other two subgroups.

Some patients in group B also had macroadenomas, but no such tumors were seen in group C. However, researchers found no association between the groups and the hormonal values, clinical findings, or surgical outcomes.

Collectively, the findings add new clues to the molecular mechanisms involved in the progression of benign pituitary tumors. They also provide new ground for developing targeted therapies, the researchers said.

From https://cushingsdiseasenews.com/2018/06/22/tumors-in-cushing-disease-patients-show-distinct-genetic-profiles-study-reports/

Study Describes 6 Common Surgical Failures in Cushing’s Disease Treatment

To help improve the effectiveness of surgical treatment of Cushing’s disease, researchers conducted a study to determine common failures. They classified these failures into six different categories.

Results were reported in the study, “Root cause analysis of diagnostic and surgical failures in the treatment of suspected Cushing’s disease,” published in the Journal of Clinical Neuroscience.

The surgical removal of lesions that secrete excess adrenocorticotropic hormone (ACTH) is the first line of treatment for patients with Cushing’s disease. But while this approach is effective in reducing cortisol levels, up to 31 percent of patients fail to achieve remission.

When initial surgery is ineffective, additional surgical procedures may help to improve patient outcomes. Medications also are used for those who do not see results from surgery.

Recognizing the factors that contribute to the failure of surgical treatment is crucial to avoiding a deterioration of patient health and to improving long-term outcomes.

Researchers at Harvard Medical School examined the clinical records of 51 patients suspected of having Cushing’s disease. These patients were followed and surgically treated at the Brigham and Women’s Hospital in Boston, from April 2008 to July 2017.

In more than 82 percent of the cases, tissue removed during surgery confirmed that the patients had excess ACTH caused by benign tumors in the adrenal gland. Among the remaining patients, two had additional ACTH-secreting tumors, four had no obvious tumor or abnormal tissue, one had a pituitary mass without ACTH secretion, and one had no evidence of tissue changes despite the detection of a tumor during exploratory surgery.

They were followed for an average of 18.3 months, during which 42 patients achieved remission as confirmed by blood tests. Of these, 34 patients did not require additional treatment; four patients needed additional surgeries to achieve control over cortisol levels; and four patients required additional radiosurgery.

Based on long-term patient outcomes, researchers were able to identify six categories of common diagnostic and surgical failures. They include:

  • persistently high cortisol levels despite the successful removal of lesions
  • the failure of tumor resection
  • recurrence of disease
  • a failure to identify the source of ACTH secretion
  • the absence of identifiable lesions during exploratory surgery
  • concurrent tumors.

While the first three are common among patients with a visible lesion on imaging scans, the latter three are characteristic of patients in whom physicians fail to detect a lesion.

Investigators believe that anticipating and recognizing these common failures may help to improve the effectiveness of surgery, symptom management, and overall treatment outcomes.

“The success of surgical intervention can be enhanced greatly by improving patient selection and surgical management by anticipating and subsequently deterring the six common failures described above,” the team concluded. They added that better imaging methods also might improve outcomes for Cushing’s disease patients.

From https://cushingsdiseasenews.com/2018/05/15/cushings-disease-surgery-6-common-failures-found-retrospective-study/

Rare Malignant Tumor of Adrenal Gland Led to Cushing’s, Girl’s Death

While adrenocortical carcinoma — a malignant tumor of the adrenal gland — appears only rarely in children, the tumor may cause secondary Cushing’s syndrome in these patients, a new case report shows.

Early diagnosis of the causes of Cushing’s syndrome could improve the prognosis of these children, researchers say.

The study, “Cushing Syndrome Revealing an Adrenocortical Carcinoma,” was published in the Open Journal of Pediatrics.

Adrenocortical carcinoma is a malignant tumor that develops in the cortex of the adrenal gland. It usually is identified by increased amounts of hormones that are produced by the adrenal glands, like cortisol.

This tumor type is very rare in children, representing fewer than two in every 1,000 pediatric tumors.

Researchers at the University Hospital Center Souro Sanou, in Burquina Faso (West Africa), described the case of a 10-year-old girl who developed this rare cancer.

The patient’s first symptoms were loss of consciousness and recurrent seizures without fever. The patient also had experienced excessive weight gain in the preceding months. At admission she was in a light state of coma and showed obesity in the face and trunk.

An initial analysis of blood, urine, and cerebrospinal fluid failed to detect any alterations, with no diabetes, kidney damage, or infection identified. And, even though no lesions or alteration were seen in the pituitary gland region, brain swelling was detected.

While in the hospital, the patient’s condition continued to deteriorate. She developed fever and difficulty speaking, while showing persistent seizures.

In the absence of a diagnosis, physicians focused on the safeguard of major vital function, control of seizures, and administration of large-spectrum antibiotics. Her condition improved slightly, regaining consciousness and control of seizures.

One month later, however, the patient developed symptoms that are commonly associated with increased levels of cortisol and male sex hormones, including obesity and early development of pubic hair.

After confirming high cortisol levels, physicians examined the patient’s abdominal region,  which revealed a tumor in the left adrenal gland.

The patient received a ketoconazole treatment and a surgery to remove the tumor was planned. But her condition worsened, with development of malignant hypertension and convulsive illness, which led to her death before the tumor was removed.

“The delay in the diagnosis and the insufficiency of the therapeutic means darken the prognosis in our context,” the researchers wrote.

“[Adrenocortical carcinoma] diagnosis should be considered in presence of virilization and early signs of puberty,” the researchers suggested. “Early diagnosis and multidisciplinary management of adrenocortical carcinoma could improve the prognosis in children.”

From https://cushingsdiseasenews.com/2018/05/04/rare-malignant-tumor-adrenal-gland-caused-cushings-case-report/

Cushing’s Patient Exhibits Cortisol-Secreting Lesions in Both Adrenal Glands

In rare cases, Cushing’s syndrome may be caused by cortisol-secreting masses in both adrenal glands, a case report shows.

The study with that finding, “ACTH-independent Cushing’s syndrome with bilateral cortisol-secreting adrenal adenomas: a case report and review of literatures” was published in BMC Endocrine Disorders.

Cushing’s syndrome results from the prolonged secretion of excess cortisol. While most cases are caused by tumors in the pituitary gland, up to 20 percent result from tumors in the adrenal glands.

Occasionally, Cushing’s syndrome is caused by masses in both adrenal glands, which may be similar or display different properties. “Determining the nature and function of bilateral adrenal masses is always a challenge in clinical practice,” researchers said.

Now, physicians at Sichuan University in China, reported the case of a 55-year-old woman who complained of difficulty breathing for more than 10 years.

The patient had developed obesity of the trunk and face over the past two years, and had been diagnosed with hypertension 10 years before. She also had high lipid levels for the past five years.

The patient was taking Avapro (irbesartan), Lopressor (metoprolol), Procardia XL (nifedipine), and statins for these disorders. No other health conditions or treatments were reported.

Physical examination showed a moon-shaped face, truncal obesity, and accumulation of fat in the back of the neck and upper back (aka buffalo hump). She also had discoloration of the lower limbs, with slight fluid accumulation and muscle weakness.

Routine blood analysis did not reveal significant changes, but hormone analysis showed high cortisol levels and low adrenocorticotropic hormone (ACTH) was low.

The amount of 24-hour urine-free cortisol was almost five times higher than the upper normal limit. Also, the patients had reduced response to corticosteroids treatment, showing even higher cortisol levels upon treatment with 1 mg dexamethasone. Additional evaluations revealed reduced bone mineral density, indicative of osteoporosis.

Together, the findings led to a diagnosis of ACTH-independent Cushing’s syndrome.

To identify what was causing Cushing’s syndrome, the team looked at the adrenal glands. They detected three lesions, one on the right side measuring 2.5 centimeters, and two on the left side, with 2.3 cm and 0.6 cm respectively. The masses in both sides were actively producing cortisol in similar proportions.

These results confirmed that the patient had Cushing’s syndrome induced by bilateral adrenal excessive cortisol secretion.

Because the patient had poor cardiac function, researchers planned a two-step operation. First, they removed the right adrenal gland laparoscopically, followed by the left adrenal gland two months later. The patient started replacement therapy with hydrocortisone, and her cortisol levels improved significantly, returning to normal levels. She also lost 4 kilograms (8.8 pounds) of body weight in the following year.

“The optimal treatment for patients with bilateral cortisol-secreting adenomas remains uncertain,” the researchers wrote. Although there are no reports of recurrence after surgical treatment, the long-term outcome of these patients remains unclear, and “lifelong follow-up of the patient is required,” they added.

Bilateral cortisol-secreting adrenal adenomas are rare, having been reported in only 15 other studies, the team wrote. Interestingly, some features reported in this study also were identified by other researchers, including the fact that bilateral cortisol-secreting adrenal lesions are more predominantly found in females during adulthood. Also, the size of the lesions commonly range between 1 to 5 centimeters when detected, and appear at approximately the same time in both adrenal glands.

Although there are no treatment guidelines for these cases, surgical removal of the lesions or adrenal glands, plus glucocorticoid replacement therapy, is the mostly used therapeutic approach. Importantly, the researchers noted that patients who underwent partial gland removal were able to withdraw from glucocorticoid replacement therapy during follow-up.

From https://cushingsdiseasenews.com/2018/05/03/cushings-patient-has-cortisol-secreting-lesions-in-both-adrenal-glands/