Thyroid dysfunction highly prevalent in Cushing’s syndrome

Central hypothyroidism is prevalent in about 1 in 2 adults with Cushing’s syndrome, and thyroid function can be restored after curative surgery for most patients, according to study findings.

“Our study findings have confirmed and greatly extended previous smaller studies that suggested a link between hypercortisolism and thyroid dysfunction but were inconclusive due to smaller sample size and short follow-up,” Skand Shekhar, MD, an endocrinologist and clinical investigator in the reproductive physiology and pathophysiology group at the National Institute of Environmental Health Sciences, NIH, told Healio. “Due to our large sample and longer follow-up, we firmly established a significant negative correlation between hypercortisolemia measures — serum and urinary cortisol, serum adrenocorticotropic hormone — and thyroid hormones triiodothyronine, free thyroxine and thyrotropin.”

Shekhar and colleagues conducted a retrospective review of two groups of adults aged 18 to 60 years with Cushing’s syndrome. The first group was evaluated at the NIH Clinical Center from 2005 to 2018 (n = 68; mean age, 43.8 years; 62% white), and the second group was evaluated from 1985 to 1994 (n = 55; mean age, 37.2 years; 89% white). The first cohort was followed for 6 to 12 months to observe the pattern of thyroid hormone changes after surgical cure of adrenocorticotropic hormone-dependent Cushing’s syndrome. The second group underwent diurnal thyroid-stimulating hormone evaluation before treatment and during remission for some cases.

Urinary free cortisol and morning thyroid hormone levels were collected for all participants. In the second group, researchers evaluated diurnal patterns of TSH concentrations with hourly measurements from 3 to 7 p.m. and midnight to 4 p.m. In the first group, adrenocorticotropic hormone and serum cortisol were measured.

In the first cohort, seven participants were receiving levothyroxine for previously diagnosed primary or central hypothyroidism. Of the remaining 61 adults, 32 had untreated central hypothyroidism. Thirteen participants had free T4 at the lower limit of normal, and 19 had subnormal levels. There were 29 adults with subnormal levels of T3 and seven with subnormal TSH.

Before surgery, 36 participants in the first group had central hypothyroidism. Six months after surgery, central hypothyroidism remained for 10 participants. After 12 months, the number of adults with central hypothyroidism dropped to six. Preoperative T3 and TSH levels were negatively associated with morning and midnight cortisol, adrenocorticotropic hormone and urinary free cortisol. In post hoc analysis, a baseline urinary free cortisol of more than 1,000 g per day was adversely associated with baseline and 6-month T3 and free T4 levels.

In the second group, there were 51 participants not on thyroid-modifying drugs who had a thyroid function test 6 or 12 months after surgery. Before surgery, free Tlevels were subnormal in 17 participants, T3 levels were subnormal in 22, and TSH levels were in the lower half of the reference range or below in all but one participant.

After surgery, two participants had below normal free T4, one had subnormal T3, and TSH levels were in the lower half of the reference range or below in 23 of 48 participants. Before surgery, there was no difference in mean TSH between daytime and nighttime. A mean 8 months after surgery, the second group had a normal nocturnal TSH surge from 1.3 mIU/L during the day to 2.17 mIU/L at night (P = .01). The nocturnal TSH increase persisted as long as 3 years in participants who had follow-up evaluations.

“We found a very high prevalence of thyroid hormone deficiency that appears to start at the level of the hypothalamus-pituitary gland and extend to the tissue level,” Shekhar said. “Some of these patients may experience thyroid hormone deficiency symptoms, such as fatigue, depression, cold intolerance, weight gain, etc, as a result of systematic and tissue-level thyroid hormone deficiency. We also noted a strong correlation between hypothyroidism and hypogonadism, which implies that hypothyroid patients are also likely to suffer adverse reproductive effects. Thus, it is imperative to perform thorough thyroid hormone assessment in patients with Cushing’s syndrome, and thyroid hormone supplementation should be considered for these patients unless cure of Cushing’s syndrome is imminent.”

Researchers said providers should routinely screen for hypothyroidism in adults with Cushing’s syndrome. Even after thyroid function is restored, regular follow-up should also be conducted.

Further research is needed to investigate thyroid dysfunction in iatrogenic Cushing’s syndrome and the impact of these findings on euthyroid sick syndrome, Shekhar said.

For more information:

Skand Shekhar, MD, can be reached at skand.shekhar@nih.gov.

From https://www.healio.com/news/endocrinology/20210208/thyroid-dysfunction-highly-prevalent-in-cushings-syndrome

Thyroid cancer: Cushing syndrome is a lesser-known warning sign – what is it?

Thyroid cancer survival rates are 84 percent for 10 years or more if diagnosed early. Early diagnosis is crucial therefore and spotting the unusual signs could be a matter of life and death. A sign your thyroid cancer has advanced includes Cushing syndrome.

What is it?

What is Cushing syndrome?

 

Cushing syndrome occurs when your body is exposed to high levels of the hormone cortisol for a long time, said the Mayo Clinic.

The health site continued: “Cushing syndrome, sometimes called hypercortisolism, may be caused by the use of oral corticosteroid medication.

“The condition can also occur when your body makes too much cortisol on its own.

“Too much cortisol can produce some of the hallmark signs of Cushing syndrome — a fatty hump between your shoulders, a rounded face, and pink or purple stretch marks on your skin.”

In a study published in the US National Library of Medicine National Institutes of Health, thyroid carcinoma and Cushing’s syndrome was further investigated.

The study noted: “Two cases of thyroid carcinoma and Cushing’s syndrome are reported.

“Both of our own cases were medullary carcinomas of the thyroid, and on reviewing the histology of five of the other cases all proved to be medullary carcinoma with identifiable amyloid in the stroma.

“A consideration of the temporal relationships of the development of the carcinoma and of Cushing’s syndrome suggested that in the two cases with papillary carcinoma these conditions could have been unrelated, but that in eight of the nine cases with medullary carcinoma there was evidence that thyroid carcinoma was present at the time of diagnosis of Cushing’s syndrome.

“Medullary carcinoma of the thyroid is also probably related to this group of tumours. It is suggested that the great majority of the tumours associated with Cushing’s syndrome are derived from cells of foregut origin which are endocrine in nature.”

In rare cases, adrenal tumours can cause Cushing syndrome a condition arising when a tumour secretes hormones the thyroid wouldn’t normally create.

Cushing syndrome associated with medullary thyroid cancer is uncommon.

The syndrome is more commonly caused by the pituitary gland overproducing adrenocorticotropic hormone (ACTH), or by taking oral corticosteroid medication.

See a GP if you have symptoms of thyroid cancer, warns the NHS.

The national health body added: “The symptoms may be caused by less serious conditions, such as an enlarged thyroid, so it’s important to get them checked.

“A GP will examine your neck and can organise a blood test to check how well your thyroid is working.

“If they think you could have cancer or they’re not sure what’s causing your symptoms, you’ll be referred to a hospital specialist for more tests.”

 

Adapted from https://www.express.co.uk/life-style/health/1351753/thyroid-cancer-signs-symptoms-cushing-syndrome

Cushing’s Syndrome Revealing Carney Complex: A Case Report

 

Carney complex (CNC) is a rare multisystem disorder, inherited in an autosomal dominant manner and characterized by distinctive spotty skin pigmentation, myxomas and endocrine abnormalities.

We report a case of a 35-year-old patient diagnosed with Cushing’s syndrome complicated with an impaired glucose tolerance (IGT) and a severe psychiatric disturbance. The diagnosis of CNC was made by having two major criteria, namely a primary pigmented nodular adrenal disease (PPNAD) and thyroid carcinoma.

Read the entire report here: Cushing’s Syndrome Revealing Carney Complex: A Case
Report

The Pituitary Gland: Small But Mighty

The pituitary gland works hard to keep you healthy, doing everything from ensuring proper bone and muscle growth to helping nursing mothers produce milk for their babies. Its functionality is even more remarkable when you consider the gland is the size of a pea.

“The pituitary is commonly referred to as the ‘master’ gland because it does so many important jobs in the body,” says Karen Frankwich, MD, a board-certified endocrinologist at Mission Hospital. “Not only does the pituitary make its own hormones, but it also triggers hormone production in other glands. The pituitary is aided in its job by the hypothalamus. This part of the brain is situated above the pituitary, and sends messages to the gland on when to release or stimulate production of necessary hormones.”

These hormones include:

  • Growth hormone, for healthy bone and muscle mass
  • Thyroid-stimulating hormone, which signals the thyroid to produce its hormones that govern metabolism and the body’s nervous system, among others
  • Follicle-stimulating and luteinizing hormones for healthy reproductive systems (including ovarian egg development in women and sperm formation in men, as well as estrogen and testosterone production)
  • Prolactin, for breast milk production in nursing mothers
  • Adrenocorticotropin (ACTH), which prompts the adrenal glands to produce the stress hormone cortisol. The proper amount of cortisol helps the body adapt to stressful situations by affecting the immune and nervous systems, blood sugar levels, blood pressure and metabolism.
  • Antidiuretic (ADH), which helps the kidneys control urine levels
  • Oxytocin, which can stimulate labor in pregnant women

The work of the pituitary gland can be affected by non-cancerous tumors called adenomas. “These tumors can affect hormone production, so you have too little or too much of a certain hormone,” Dr. Frankwich says. “Larger tumors that are more than 1 centimeter, called macroadenomas, can also put pressure on the area surrounding the gland, which can lead to vision problems and headaches. Because symptoms can vary depending on the hormone that is affected by a tumor, or sometimes there are no symptoms, adenomas can be difficult to pinpoint. General symptoms can include nausea, weight loss or gain, sluggishness or weakness, and changes in menstruation for women and sex drive for men.”

If there’s a suspected tumor, a doctor will usually run tests on a patient’s blood and urine, and possibly order a brain-imaging scan. An endocrinologist can help guide a patient on the best course of treatment, which could consist of surgery, medication, radiation therapy or careful monitoring of the tumor if it hasn’t caused major disruption.

“The pituitary gland is integral to a healthy, well-functioning body in so many ways,” Dr. Frankwich says. “It may not be a major organ you think about much, but it’s important to know how it works, and how it touches on so many aspects of your health.”

Learn more about Mission Hospital. Learn more about Dr. Frankwich.

From http://www.stjhs.org/HealthCalling/2016/December/The-Pituitary-Gland-Small-but-Mighty.aspx

Pituitary Gland: Normal Function and Assessment

Abstract

This computer-based, interactive module introduces preclinical medical students to normal pituitary function and outlines its assessment. Solid understanding of these topics is requisite to learning clinical disorders of the pituitary.

Existing resources largely target learners at earlier or later stages of training; thus, we created this resource to address needs of medical students during a first- or second-year endocrine course. A module format was selected to promote interactive, independent learning.

Two cohorts of medical students completed the 40-minute module: 172 second-year students who had completed a year of basic sciences in the traditional curriculum and 180 foundation-phase students in a three-semester combined basic and clinical sciences curriculum (due to a change in the medical school curriculum at our institution). In both instances, the module was completed before start of clinical pituitary content. A static set of PowerPoint slides accompanied the module to facilitate note taking.

Test Your Knowledge slides were inserted to ensure grasp of key terms/concepts before moving to subsequent slides. A short question-and-answer session was held following module completion to clarify points of confusion. Students rated effectiveness of the module as 4.6 out of 5, commenting on its clarity, organization, high-yield nature, and utility in preparing for clinical material.

Faculty noted greater understanding of foundational pituitary principles and more engaging discussions. The percentage of pituitary-related questions answered correctly on the midterm exam increased.

Finally, success of the pituitary module prompted development of adrenal, thyroid, and parathyroid modules that now comprise the Endocrine Organs Introduction Series in our curriculum.

Citation

Kirk D, Smith KW. Pituitary gland: normal function and assessment. MedEdPORTAL Publications. 2016;12:10430. http://dx.doi.org/10.15766/mep_2374-8265.10430

Educational Objectives

After completing this module, the learner will be able to:

  1. Describe the normal function and regulation of the pituitary gland, including names and actions of the anterior and posterior pituitary hormones.
  2. Understand the basic approach to laboratory assessment of the pituitary.
  3. Differentiate between anterior and posterior pituitary origin, function, and regulation.
  4. List the hormones produced by the pituitary gland.
  5. Discuss for each pituitary hormone: hypothalamic stimulating/inhibiting factors and their clinical uses, basic physiologic function, and regulation (feedback loop).
  6. Describe factors that affect growth hormone levels.
  7. Understand the tests for growth hormone excess and deficiency.
  8. Define a primary versus secondary endocrine disorder.

Keywords

  • Endocrine, Endocrinology, Pituitary, Module, Preclinical Medical Education

More information at https://www.mededportal.org/publication/10430

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