Basics: 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.”

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

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Basics: Testing: IGF-1 (Insulin-like growth factor 1)

Aim—To contribute to the debate about whether growth hormone (GH) and insulin-like growth factor 1 (IGF-1) act independently on the growth process.

Methods—To describe growth in human and animal models of isolated IGF-1 deficiency (IGHD), such as in Laron syndrome (LS; primary IGF-1 deficiency and GH resistance) and IGF-1 gene or GH receptor gene knockout (KO) mice.

Results—Since the description of LS in 1966, 51 patients were followed, many since infancy. Newborns with LS are shorter (42–47 cm) than healthy babies (49–52 cm), suggesting that IGF-1 has some influence on intrauterine growth. Newborn mice with IGF-1 gene KO are 30% smaller. The postnatal growth rate of patients with LS is very slow, the distance from the lowest normal centile increasing progressively. If untreated, the final height is 100–136 cm for female and 109–138 cm for male patients. They have acromicia, organomicria including the brain, heart, gonads, genitalia, and retardation of skeletal maturation. The availability of biosynthetic IGF-1 since 1988 has enabled it to be administered to children with LS. It accelerated linear growth rates to 8–9 cm in the first year of treatment, compared with 10–12 cm/year during GH treatment of IGHD. The growth rate in following years was 5–6.5 cm/year.

Conclusion—IGF-1 is an important growth hormone, mediating the protein anabolic and linear growth promoting effect of pituitary GH. It has a GH independent growth stimulating effect, which with respect to cartilage cells is possibly optimised by the synergistic action with GH.

Keywords: insulin-like growth factor I, growth hormones, Laron syndrome, growth

In recent years, new technologies have enabled many advances in the so called growth hormone (GH) axis (fig 1). Thus, it has been found that GH secretion from the anterior pituitary is regulated not only by GH releasing hormone (GHRH) and somatostatin (GH secretion inhibiting hormone), but also by other hypothalamic peptides called GH secretagogues, which seem to act in synergism with GHRH by inhibiting somatostatin. One of these has been cloned and named Ghrelin. The interplay between GHRH and somatostatin induces a pulsatile GH secretion, which is highest during puberty. GH induces the generation of insulin-like growth factor 1 (IGF-1, also called somatomedin 1) in the liver and regulates the paracrine production of IGF-1 in many other tissues.

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The cascade of the growth hormone axis. CNS, central nervous system; GH, growth hormone; GHBP, GH binding protein; GH-S, GH secretagogues; IGF-1, insulin-like growth factor 1; IGFBPs, IGF binding proteins; +, stimulation; –, inhibition.

IGF-1

IGF-1 and IGF-2 were identified in 1957 by Salmon and Daughaday and designated “sulphation factor” by their ability to stimulate 35-sulphate incorporation into rat cartilage. Froesch et al described the non-suppressible insulin-like activity (NSILA) of two soluble serum components (NSILA I and II). In 1972, the labels sulphation factor and NSILA were replaced by the term “somatomedin”, denoting a substance under control and mediating the effects of GH. In 1976, Rinderknecht and Humbel isolated two active substances from human serum, which owing to their structural resemblance to proinsulin were renamed “insulin-like growth factor 1 and 2” (IGF-1 and 2). IGF-1 is the mediator of the anabolic and mitogenic activity of GH.

CHEMICAL STRUCTURE

The IGFs are members of a family of insulin related peptides that include relaxin and several peptides isolated from lower invertebrates. IGF-1 is a small peptide consisting of 70 amino acids with a molecular weight of 7649 Da. Similar to insulin, IGF-1 has an A and B chain connected by disulphide bonds. The C peptide region has 12 amino acids. The structural similarity to insulin explains the ability of IGF-1 to bind (with low affinity) to the insulin receptor.

THE IGF-1 GENE

The IGF-1 gene is on the long arm of chromosome 12q23–23. The human IGF-1 gene consists of six exons, including two leader exons, and has two promoters.

IGF binding proteins (IGFBPs)

In the plasma, 99% of IGFs are complexed to a family of binding proteins, which modulate the availability of free IGF-1 to the tissues. There are six binding proteins. In humans, almost 80% of circulating IGF-1 is carried by IGFBP-3, a ternary complex consisting of one molecule of IGF-1, one molecule of IGFBP-3, and one molecule of an 88 kDa protein named acid labile subunit. IGFBP-1 is regulated by insulin and IGF-1; IGFBP-3 is regulated mainly by GH but also to some degree by IGF-1.

The IGF-1 receptor

The human IGF-1 receptor (type 1 receptor) is the product of a single copy gene spanning over 100 kb of genomic DNA at the end of the long arm of chromosome 15q25–26. The gene contains 21 exons (fig 2) and its organisation resembles that of the structurally related insulin receptor (fig 3). The type 1 IGF receptor gene is expressed by almost all tissues and cell types during embryogenesis. In the liver, the organ with the highest IGF-1 ligand expression, IGF-1 receptor mRNA is almost undetectable, possibly because of the “downregulation” of the receptor by the local production of IGF-1. The type 1 IGF receptor is a heterotetramer composed of two extracellular spanning α subunits and transmembrane β subunits. The α subunits have binding sites for IGF-1 and are linked by disulphide bonds (fig 3). The β subunit has a short extracellular domain, a transmembrane domain, and an intracellular domain. The intracellular part contains a tyrosine kinase domain, which constitutes the signal transduction mechanism. Similar to the insulin receptor, the IGF-1 receptor undergoes ligand induced autophosphorylation. The activated IGF-1 receptor is capable of phosphorylating other tyrosine containing substrates, such as insulin receptor substrate 1 (IRS-1), and continues a cascade of enzyme activations via phosphatidylinositol-3 kinase (PI3-kinase), Grb2 (growth factor receptor bound protein 2), Syp (a phophotyrosine phosphatase), Nck (an oncogenic protein), and Shc (src homology domain protein), which associated to Grb2, activates Raf, leading to a cascade of protein kinases including Raf, mitogen activated protein (MAP) kinase, 5 G kinase, and others.

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Type 1 insulin-like growth factor receptor gene and mRNA. Reproduced with permission from Werner.

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Resemblance between the insulin and insulin-like growth factor 1 (IGF-1) receptors.

Physiology

IGF-1 is secreted by many tissues and the secretory site seems to determine its actions. Most IGF-1 is secreted by the liver and is transported to other tissues, acting as an endocrine hormone. IGF-1 is also secreted by other tissues, including cartilagenous cells, and acts locally as a paracrine hormone (fig 4). It is also assumed that IGF-1 can act in an autocrine manner as an oncogene. The role of IGF-1 in the metabolism of many tissues including growth has been reviewed recently.

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Paracrine insulin-like growth factor 1 (IGF-1) secretion and endocrine IGF-1 targets in the various zones of the epiphyseal cartilage growth zone.

The following is an analysis of whether IGF-1, the anabolic effector hormone of pituitary GH, is the “real growth hormone”.

Is IGF-1 “a” or “the” growth hormone?

The discussion on the role of IGF-1 in body growth will be based on growth in states of IGF-1 deficiency and the effects of exogenous IGF-1 administration. Experiments in nature (gene deletion or gene mutations) or experimental models in animals, such as gene knockouts, help us in this endeavour. In 1966 and 1968, we described a new type of dwarfism indistinguishable from genetic isolated GH deficiency (IGHD), but characterised by high serum GH values. Subsequent studies revealed that these patients cannot generate IGF-1.

This syndrome of GH resistance (insensitivity) was named by Elders et al as Laron dwarfism, a name subsequently changed to Laron syndrome (LS). Molecular studies revealed that the causes of GH resistance are deletions or mutations in the GH receptor gene, resulting in the failure to generate IGF-1 and a reduction in the synthesis of several other substances, including IGFBP-3. This unique model in humans has enabled the study of the differential effects of GH and IGF-1.

Growth and development in congenital (primary) IGF-1 deficiency (LS)

Our group has studied and followed 52 patients (many since birth) throughout childhood, puberty, and into adulthood. We found that newborns with LS are slightly shorter at birth (42–47 cm) than healthy babies (49–52 cm), suggesting that IGF-1 has some influence on intrauterine linear growth. This fact is enforced by the findings that already at birth, and throughout childhood, skeletal maturation is retarded, as is organ growth. These growth abnormalities include a small brain (as expressed by head circumference), a small heart (cardiomicria), and acromicria (small chin, resulting from underdevelopment of the facial bones, small hands, and small feet). IGF-1 deficiency also causes underdevelopment and weakness of the muscular system, and impairs and weakens hair and nail growth. These findings are identical to those described in IGHD. IGF-1 deficiency throughout childhood causes dwarfism (final height if untreated, 100–135 cm in female and 110–142 cm in male patients), with an abnormally high upper to lower body ratio. One patient reported from the UK was found to have a deletion of exons 4 and 5 of the IGF-1 gene and he too was found to have severe growth retardation.

Impaired growth and skeletal development in the absence of IGF-1 were confirmed in mice using knockout (KO) of the IGF-1 gene or GH receptor gene.

Knockout of the IGF-1 gene or the IGF-1 receptor gene reduces the size of mice by 40–45%. Lack of the IGF-1 receptor is lethal at birth in mice owing to respiratory failure caused by impaired development of the diaphragm and intercostal muscles. In another model, the mice remained alive and their postnatal growth was reduced.

In conclusion, findings in humans and in animals show that IGF-1 deficiencies causes pronounced growth retardation in the presence of increased GH values.

The following is a summary of the results of the growth stimulating effects of the administration of exogenous IGF-1 to children and experimental data.

Growth promoting effects of IGF-1

The first demonstration that exogenous IGF-1 stimulates growth was the administration of purified hormone to hypophysectomised rats. After the biosynthesis of IGF-1 identical to the native hormone, trials of its use in humans were begun; first in adults and then in children. Our group was the first to introduce long term administration of biosynthetic IGF-1 to children with primary IGF-1 deficiency—primary GH insensitivity or LS. The finding that daily IGF-1 administration raises serum alkaline phosphatose, which is an indicator of osteoblastic activity, and serum procollagen, in addition to IGFBP-3, led to long term treatment. Treatment of patients with LS was also initiated in other parts of the world. The difference between us and the other groups was that we used a once daily dose, whereas the others administered IGF-1 twice daily. Table 1 compares the linear growth response of children with LS treated by four different groups. It can be seen that before treatment the mean growth velocity was 3–4.7 cm/year and that this increased after IGF-1 treatment to 8.2–9.1 cm/year, followed by a lower velocity of 5.5–6.4 cm/year in the next two years. (In GH treatment the highest growth velocity registered is also in the first year of treatment.) Figure 5 illustrates the growth response to IGF-1 in eight children during the first years of treatment. Ranke and colleagues reported that two of their patients had reached the third centile (Tanner), as did the patient of Krzisnik and Battelino; however, most patients did not reach a normal final height. The reasons may be late initiation of treatment, irregular IGF-1 administration, underdosage, etc. Ranke et al conclude that long term treatment of patients with LS promoted growth and, if treatment is started at an early age, there is a considerable potential for achieving height normalisation. Because no patient in our group was treated since early infancy to final height we cannot confirm this opinion.

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Growth velocity before and during insulin-like growth factor 1 (IGF-1) treatment. Note that in infancy, when the non-growth hormone/IGF-1 dependent growth velocity is relatively high (but low for age), the change induced by IGF-1 administration is less than in older children.

Table 1

Linear growth response of children with Laron syndrome treated by means of insulin-like growth factor 1 (IGF-1)

At start Growth velocity (cm/year) Year of treatment
Authors Year Ref. N Age range (years) BA (years) Ht SDS (m) IGF-1 dose (μg/kg/day) 0 1st 2nd 3rd
(n = 26) (n = 18)
Ranke et al 1995 31 3.7–19 1.8–13.3 −6.5 40–120 b.i.d. 3.9 (1.8) 8.5 (2.1) 6.4 (2.2)
(n = 5) (n = 5) (n = 1)
Backeljauw et al 1996 5 2–11 0.3–6.8 −5.6 80–120 b.i.d. 4.0 9.3 6.2 6.2
(n = 9) (n = 6) (n = 5)
Klinger and Laron 1995 9 0.5–14 0.2–11 −5.6 150–200 i.d 4.7 (1.3) 8.2 (0.8) 6 (1.3) 4.8 (1.3)*
(n = 15) (n = 15) (n = 6)
Guevarra-Aguirre et al 1997 15 3.1–17 4.5–9.3 120 b.i.d. 3.4 (1.4) 8.8 (11) 6.4 (1.1) 5.7 (1.4)
(n = 8) (n = 8)
Guevarra-Aguire et al 8 80 b.i.d. 3.0 (1.8) 9.1 (2.2) 5.6 (2.1)

Growth velocity values are mean (SD).

*The younger children had a growth velocity of 5.5 and 6.5 cm/year.

BA, bone age; b.i.d., twice daily; CA, chronological age; i.d., once daily; Ht SDS, height standard deviation score.

When the growth response to GH treatment in infants with IGHD was compared with that of IGF-1 in infants with LS we found that the infants with IGHD responded faster and better than those with LS. However, the small number of patients and the differences in growth retardation between the two groups makes it difficult to reach a conclusion.

Both hormones stimulated linear growth, but GH seemed more effective than IGF-1. One cause may be the greater growth deficit of the infants with LS than those with IGHD, an insufficient dose of IGF-1, or that there is a need for some GH to provide an adequate stem cell population of prechondrocytes to enable full expression of the growth promoting action of IGF-1, as postulated by Green and colleagues and Ohlson et al. All the above findings based on a few clinical studies with small groups of patients and a few experimental studies remain at present controversial. The crucial question is whether there are any, and if so, whether there are sufficient IGF-1 receptors in the “progenitor cartilage zone” of the epiphyseal cartilage (fig 4) to respond to endocrine and exogenous IGF-1. Using the mandibular condyle of 2 day old ICR mice, Maor et al showed that these condyles, which resemble the epiphyseal plates of the long bones, contain IGF-1 and high affinity IGF-1 receptors also in the chondroprogenitor cell layers, which enables them to respond to IGF-1 in vitro.

Sims et al, using mice with GH receptor KO showed that IGF-1 administration stimulates the growth (width) of the tibial growth plate and that IGF-1 has a GH independent effect on the growth plate. These findings are similar to those found when treating hypophysectomised rats with IGF-1.

In conclusion, IGF-1 is an important growth hormone, mediating the anabolic and linear growth promoting effect of pituitary GH protein. It has a GH independent growth stimulating effect, which with respect to cartilage cells is possibly optimised by the synergistic action with GH.

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Basics: Testing: Dex Tests

Dexamethasone suppression test measures whether adrenocorticotrophic hormone (ACTH) secretion by the pituitary can be suppressed.

How the Test is Performed

During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medicine. Afterward, your blood is drawn so that the cortisol level in your blood can be measured.

There are two different types of dexamethasone suppression tests: low dose and high dose. Each type can either be done in an overnight (common) or standard (3-day) method (rare). There are different processes that may be used for either test. Examples of these are described below.

Common:

  • Low-dose overnight — You will get 1 milligram (mg) of dexamethasone at 11 p.m., and a health care provider will draw your blood the next morning at 8 a.m. for a cortisol measurement.
  • High-dose overnight — The provider will measure your cortisol on the morning of the test. Then you will receive 8 mg of dexamethasone at 11 p.m. Your blood is drawn the next morning at 8 a.m. for a cortisol measurement.

Rare:

  • Standard low-dose — Urine is collected over 3 days (stored in 24-hour collection containers) to measure cortisol. On day 2, you will get a low dose (0.5 mg) of dexamethasone by mouth every 6 hours for 48 hours.
  • Standard high-dose — Urine is collected over 3 days (stored in 24-hour collection containers) for measurement of cortisol. On day 2, you will receive a high dose (2 mg) of dexamethasone by mouth every 6 hours for 48 hours.

Read and follow the instructions carefully. The most common cause of an abnormal test result is when instructions are not followed.

How to Prepare for the Test

The provider may tell you to stop taking certain medicines that can affect the test, including:

  • Antibiotics
  • Anti-seizure drugs
  • Medicines that contain corticosteroids, such as hydrocortisone, prednisone
  • Estrogen
  • Oral birth control (contraceptives)
  • Water pills (diuretics)

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

This test is done when the provider suspects that your body is producing too much cortisol. It is done to help diagnose Cushing syndrome and identify the cause.

The low-dose test can help tell whether your body is producing too much ACTH. The high-dose test can help determine whether the problem is in the pituitary gland (Cushing disease) or from a different site in the body (ectopic).

Dexamethasone is a man-made (synthetic) steroid that binds to the same receptor as cortisol. Dexamethasone reduces ACTH release in normal people. Therefore, taking dexamethasone should reduce ACTH level and lead to a decreased cortisol level.

If your pituitary gland produces too much ACTH, you will have an abnormal response to the low-dose test. But you can have a normal response to the high-dose test.

Normal Results

Cortisol level should decrease after you receive dexamethasone.

Low dose:

  • Overnight — 8 a.m. plasma cortisol lower than 1.8 micrograms per deciliter (mcg/dL) or 50 nanomoles per liter (nmol/L)
  • Standard — Urinary free cortisol on day 3 lower than 10 micrograms per day (mcg/day) or 280 nmol/L

High dose:

  • Overnight — greater than 50% reduction in plasma cortisol
  • Standard — greater than 90% reduction in urinary free cortisol

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal response to the low-dose test may mean that you have abnormal release of cortisol (Cushing syndrome). This could be due to:

The high-dose test can help tell a pituitary cause (Cushing disease) from other causes. An ACTH blood test may also help identify the cause of high cortisol.

Abnormal results vary based on the condition causing the problem.

Cushing syndrome caused by an adrenal tumor:

  • Low-dose test — no decrease in blood cortisol
  • ACTH level — low
  • In most cases, the high-dose test is not needed

Ectopic Cushing syndrome:

  • Low-dose test — no decrease in blood cortisol
  • ACTH level — high
  • High-dose test — no decrease in blood cortisol

Cushing syndrome caused by a pituitary tumor (Cushing disease)

  • Low-dose test — no decrease in blood cortisol
  • High-dose test — expected decrease in blood cortisol

False test results can occur due to many reasons, including different medicines, obesity, depression, and stress. False results are more common in women than men.

Most often, the dexamethasone level in the blood is measured in the morning along with the cortisol level. For the test result to be considered accurate, the dexamethasone level should be higher than 200 nanograms per deciliter (ng/dL) or 4.5 nanomoles per liter (nmol/L). Dexamethasone levels that are lower can cause a false-positive test result.

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Multiple punctures to locate veins
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

Alternative Names

DST; ACTH suppression test; Cortisol suppression test

References

Chernecky CC, Berger BJ. Dexamethasone suppression test – diagnostic. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:437-438.

Guber HA, Oprea M, Russell YX. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. St Louis, MO: Elsevier; 2022:chap 25.

Newell-Price JDC, Auchus RJ. The adrenal cortex. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 15.

Review Date 5/13/2021

Updated by: Brent Wisse, MD, Board Certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

From https://medlineplus.gov/ency/article/003694.htm

ℹ️ Basics: Cushing’s Syndrome vs Cushing’s Disease

What is Cushing’s syndrome?

Any condition that causes the adrenal gland to produce excessive cortisol results in the disorder Cushing’s syndrome. Cushing syndrome is characterized by facial and torso obesity, high blood pressure, stretch marks on the belly, weakness, osteoporosis, and facial hair growth in females.

Cushing’s syndrome has many possible causes including tumors within the adrenal gland, adrenal gland stimulating hormone (ACTH) produced from cancer such as lung cancer, and ACTH excessively produced from a pituitary tumors within the brain. ACTH is normally produced by the pituitary gland (located in the center of the brain) to stimulate the adrenal glands’ natural production of cortisol, especially in times of stress.

When a pituitary tumor secretes excessive ACTH, the disorder resulting from this specific form of Cushing’s syndrome is referred to as Cushing’s disease.

As an aside, it should be noted that doctors will sometimes describe certain patients with features identical to Cushing’s syndrome as having ‘Cushingoid’ features. Typically, these features are occurring as side effects of cortisone-related medications, such as prednisone and prednisolone.

ℹ️ Cushing’s Basics: The Endocrine System

The endocrine system is a complex network of glands and organs. It uses hormones to control and coordinate your body’s metabolism, energy level, reproduction, growth and development, and response to injury, stress, and mood. The following are integral parts of the endocrine system:

 

  • Hypothalamus. The hypothalamus is located at the base of the brain, near the optic chiasm where the optic nerves behind each eye cross and meet. The hypothalamus secretes hormones that stimulate or suppress the release of hormones in the pituitary gland, in addition to controlling water balance, sleep, temperature, appetite, and blood pressure.
  • Pineal body. The pineal body is located below the corpus callosum, in the middle of the brain. It produces the hormone melatonin, which helps the body know when it’s time to sleep.
  •  Pituitary . The pituitary gland is located below the brain. Usually no larger than a pea, the gland controls many functions of the other endocrine glands.
  • Thyroid and parathyroid. The thyroid gland and parathyroid glands are located in front of the neck, below the larynx (voice box). The thyroid plays an important role in the body’s metabolism. The parathyroid glands play an important role in the regulation of the body’s calcium balance.
  • Thymus. The thymus is located in the upper part of the chest and produces white blood cells that fight infections and destroy abnormal cells.
  •  Adrenal gland . An adrenal gland is located on top of each kidney. Like many glands, the adrenal glands work hand-in-hand with the hypothalamus and pituitary gland. The adrenal glands make and release corticosteroid hormones and epinephrine that maintain blood pressure and regulate metabolism.
  •  Pancreas . The pancreas is located across the back of the abdomen, behind the stomach. The pancreas plays a role in digestion, as well as hormone production. Hormones produced by the pancreas include insulin and glucagon, which regulate levels of blood sugar.
  • Ovary. A woman’s ovaries are located on both sides of the uterus, below the opening of the fallopian tubes (tubes that extend from the uterus to the ovaries). In addition to containing the egg cells necessary for reproduction, the ovaries also produce estrogen and progesterone.
  • Testis. A man’s testes are located in a pouch that hangs suspended outside the male body. The testes produce testosterone and sperm.

ℹ️ Basics: Pituitary Tumors and Headaches

Headaches are a common complaint in patients with pituitary tumors. Although many patients presumably have headaches which are unrelated to their pituitary tumor, there are several important direct and indirect mechanisms by which pituitary tumors may elicit or exacerbate headaches. Pituitary tumors may directly provoke headaches by eroding laterally into the cavernous sinus, which contains the first and second divisions of the trigeminal nerve, by involvement of the dural lining of the sella or diaphragma sella (which are innervated by the trigeminal nerve), or via sinusitis, particularly after transsphenoidal surgery. Headache pain in these situations is typically characterized by steady, bifrontal or unilateral frontal aching (ipsilateral to tumor). In some instances, pain is localized in the midface (either because of involvement of the second division of the trigeminal or secondary to sinusitis).

In contrast to the insidious, subacute development of headaches in most patients with pituitary tumors, patients with pituitary apoplexy may experience acute, severe headaches, perhaps associated with signs and symptoms of meningeal irritation (stiff neck, photophobia), CSF pleocytosis or occulomotor paresis. Routine CT scans of the head occasionally skip the sella, hence the presence of blood or a mass within the sella may not be detected and patients can be misdiagnosed with meningitis or aneurysm. Because pituitary apoplexy represents a neurosurgical emergency, MRI should be used in patients with symptoms suggestive of this disorder. A subacute form of pituitary apoplexy has also been reported. Patients with subacute pituitary apoplexy experience severe and/or frequent headaches over weeks to months and have heme products within the sella on MRI scans.

In most instances, headaches are not attributable to direct effects of the pituitary tumor and indirect causes must be considered. Generally, indirect effects of pituitary tumors are caused by reduced secretion of pituitary hormones and are manifested by promotion of “vascular” headaches (e.g., migraine). The major exception to this rule relates to the potential for acromegalic patients to develop headaches secondary to cervical osteoarthritis. Vascular headaches may be exacerbated in association with disruption of normal menstrual cyclicity and impaired gonadal steroid secretion (e.g., from hyperprolactinemia or gonadotropin deficiency). Hyperprolactinemia, hypothyroidism and hyperthyroidism may also have direct effects, independent of gonadal hormones. Headaches are common in acromegaly, and in the majority of cases the etiology is not well understood.

Finally, drug management of pituitary tumors may inadvertently impact headaches. Octreotide results in extremely rapid headache improvement with patients with acromegaly. The rapid time course suggests it is not due to lowering of GH levels. Octreotide also has a dramatic beneficial effect on migraine and may be producing relief of headache by vascular mechanisms. Occasionally severe headaches surface in acromegalic patients after reduction or discontinuation of octreotide, as a “withdrawal” phenomenon.|

Bromocriptine or other dopamine agonists occasionally trigger severe headaches. When this occurs, it is important to recognize that bromocriptine has been reported as a cause of pituitary apoplexy, and it may be necessary to perform an MRI or CT to rule out infarction or hemorrhage within the pituitary. Once it is established that the patient is not infarcting the pituitary, it is generally safe to treat the headaches symptomatically (not with an ASA containing drug) and consider alternative therapies for the prolactinoma if the problem remains severe.

Pituitary tumor patients with vascular headaches are generally quite responsive to standard prophylactic migraine drugs (e.g., tricyclic antidepressants, verapamil and beta-blockers). It is best to begin therapy with very low-dose medication (e.g., 10 mg of amitriptyline at bedtime) and resist the impulse to escalate the dose rapidly to higher levels. Often patients have an excellent response to 10-30 mg of a tricyclic antidepressant, although it may take up to six or more weeks to reach the ultimate benefit. The choice of tricyclic antidepressant should be based upon the desired side effects (e.g., either more sedation or less sedation) The newer, serotonin-selective antidepressants are generally less effective for headaches than tricyclics, although some patients do respond nicely to these agents. In some cases it may be necessary to use combination therapy (e.g., verapamil plus a tricyclic).

From https://www.massgeneral.org/neurosurgery/treatments-and-services/pituitary-tumors-and-headaches?fbclid=IwAR2iBMjf5VNvw2_ucalXikyIZIh3dJuYu0Kk6P1jhQ2IDnDj9ubkPO4Zl9A

ℹ️ Basics: Cushing’s Syndrome Overview

Cushing’s syndrome is a rare disorder that occurs when the body is exposed to too much cortisol. Cortisol is produced by the body and is also used in corticosteroid drugs. Cushing’s syndrome can occur either because cortisol is being overproduced by the body or from the use of drugs that contain cortisol (like  prednisone ).

Cortisol is the body’s main stress hormone. Cortisol is secreted by the adrenal glands in response to the secretion of adrenocorticotropic hormone (ACTH) by the pituitary. One form of Cushing’s syndrome may be caused by an oversecretion of ACTH by the pituitary leading to an excess of cortisol.

Cortisol has several functions, including the regulation of inflammation and controlling how the body uses carbohydrates, fats, and proteins. Corticosteroids such as prednisone, which are often used to treat inflammatory conditions, mimic the effects of cortisol.

Stay tuned for more basic info…

🎤 4th Pituitary Update | Perelman School of Medicine at the University of Pennsylvania

Friday, October 8, 2021

7:45 am – 4:00 pm

OVERVIEW

This conference will present the newest approaches and techniques in the diagnosis and treatment of pituitary adenomas, including acromegaly and Cushing’s disease. Diagnosis and treatment will be covered from the interdisciplinary and interprofessional perspective of endocrinology, radiology, neuro-ophthalmology, neurosurgery, and radiation oncology. Didactic presentations will include case discussions. The conference format, although virtual will provide a significant opportunity for interaction with expert faculty. A simulcast of transsphenoidal surgery will occur throughout the conference with real-time discussion and case review of the progress on the day of surgery, post-op management, surveillance and follow-up care.

Participants will leave with up-to-date, practical information and written resources including: DDAVP stimulation protocol for Cushing’s disease localization, perioperative glucocorticoid and salt-water monitoring protocol, clinic note templates, laboratory testing panels, “Sick Day Rules” letter for patients with adrenal insufficiency.  These materials will have immediate clinical application and help streamline care of pituitary patients at the office and during hospitalizations.

LEARNING OBJECTIVES – CME

Upon completion of this conference, participants should be able to:

  • Evaluate a sellar mass to determine if it is a pituitary adenoma or other lesion
  • Identify the value and limits of MRI in evaluating a sellar mass
  • List the potential and limits of endoscopic transsphenoidal surgery for pituitary adenoma
  • Manage, medically, a patient following endonasal surgery
  • List the different types of radiation, including linear accelerator (IMRT, Cyberknife), gamma radiation, (Gamma Knife) and proton beam
  • Treat, medically, patients who have acromegaly and Cushing’s disease
  • Apply multidisciplinary, interprofessional and interdisciplinary approach in the management of pituitary disease

LEARNING OBJECTIVES – PATIENTS

  • Upon completion of this course patients, families and advocates will be able to:
  • Identify the latest advances in pituitary tumor treatment
  • Demonstrate familiarity with the terminology and technical aspects of pituitary tumor care
  • Demonstrate patient-active behavior in working with the healthcare team to make ongoing treatment decisions

WHO SHOULD ATTEND

This activity has been designed for endocrinologists, neurosurgeons, ophthalmologists, gynecologists, general radiologists, nurse practitioners, nurses, residents and fellows. Additionally, patients and their caregivers, family members, advocates and members of the public who may benefit from understanding current innovative approaches to pituitary tumor care are invited.

For additional information please contact Hyacen Putmon.

Register Now

💉 In Manchester? New Endocrinology Unit

Stockport, NHS FT, has opened a new specialist endocrinology investigation unit, making it one of only two clinics of its type in Greater Manchester. One of the main benefits is, it will ensure patients with potential endocrinology conditions are treated faster, with more accurate assessments carried out. The specialist unit will also allow patients to receive their diagnosis as outpatients, without the need for an inpatient stay.

Endocrinology is the study and management of hormone related disorders which are often complex, and include some rare conditions. If hormones become unbalanced, they can lead to various conditions known as endocrine disorders. These are the conditions which are diagnosed and treated by the clinic’s consultants. Some of the examples include thyroid problems, adrenal nodules, which may lead to Cushing’s syndrome with hypertension, diabetes and osteoporosis; or pituitary nodules, which may lead to pituitary deficiency or cause blindness.

Some of these conditions are difficult to diagnose, and simple blood tests are not enough. In these cases, ‘dynamic tests’ are needed, which require significant expertise in how they are performed and how the results are interpreted. Previously these specialised tests required an inpatient stay, where patients would often have to wait for over few months.

Dr Daniela Aflorei, Consultant in Diabetes and Endocrinology for Stockport FT, who runs the clinic, said “I am delighted we are now able to provide a specialist Endocrinology service at our hospital which can provide quicker and more convenient care for our patients.

“With these conditions, swift diagnosis is very important for effective treatment, so this is going to have real benefit for people’s lives. I’d like to thank the many members of staff who helped us set up the new clinic and made it possible.”

The clinic has reduced the typical waiting time significantly, due to the clinic being run by endocrinology specialists. Patients have the opportunity to meet the endocrinology specialist nurses, helping understand the reasons for the tests to be discussed, keeping them informed in all aspects of their treatment.

The specialist clinic is run on one day each week, and is expected to benefit around 300 patients a year.

From https://www.nationalhealthexecutive.com/articles/specialist-unit-improve-endocrinology-care

🎥 Pituitary Tumors and Treatments

Pituitary tumors start in the pituitary gland. They’re usually benign (not cancerous) and rarely spread to other parts of the body.

Dr. Borghei-Razavi discusses pituitary tumors and treatments through minimally invasive surgical approaches offered at Cleveland Clinic Florida.