Hypopituitarism and COVID-19 – exploring a possible bidirectional relationship?

As of September 1, 2021, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the virus responsible for the coronavirus disease 2019 (COVID-19), has infected over 219 million and caused the deaths of over 4.5 million worldwide. Although COVID-19 has been traditionally associated with its ability to cause varied symptoms resembling acute respiratory distress syndrome (ARDS), emerging scientific evidence has demonstrated that SARS-CoV-2 causes much more damage beyond its effects on the upper respiratory tract.

To this end, in a recent study published in Reviews in Endocrine and Metabolic Disorders, the researchers discuss the extra-pulmonary manifestations of COVID-19.

Risk factors for severe COVID-19

It is now a well-known fact that the likelihood of people falling severely ill or dying from COVID-19 is increases if these individuals are obese, or have certain comorbidities like diabetes mellitus (DM), vitamin D deficiency, and vertebral fractures (VFs).

Any abnormality in the pituitary gland may lead to metabolic disorders, impaired immunity, and a host of other conditions that also make the body susceptible to infections. Since such conditions are common in patients with COVID-19 as well, it has been hypothesized that there might be a relationship between COVID-19 and pituitary gland disorders.

On the other hand, researchers have also observed that COVID-19 causes increased severity of pituitary-related disorders, and even pituitary apoplexy, which is a condition defined as internal bleeding or impaired blood supply in the pituitary gland. A group of Italian researchers has reviewed this bidirectional relationship between the pituitary gland abnormalities and COVID-19 in their study recently published in Reviews in Endocrine and Metabolic Disorders.

The link between pituitary gland abnormalities and COVID19

The pituitary gland releases hormones that regulate and control some of the most important functions of the body like growth, metabolism, energy levels, bone health, mood swings, vision, reproduction, and immunity, to name a few. The inability of the pituitary gland to release one or more of these hormones is known as ‘hypopituitarism.’  Factors responsible for hypopituitarism include traumatic brain injury, pituitary adenomas (tumors), genetic mutations, as well as infiltrative and infectious diseases.

Hypopituitarism can lead to severe cases of DM, growth hormone deficiency (GHD), abnormal lipid profile, obesity, arterial hypertension, and immune dysfunctions. Interestingly, similar consequences of COVID-19 have also been reported.

SARS-CoV-2 infects the human body by binding to a special class of receptors known as the angiotensin-converting enzyme 2 (ACE2) receptors. These receptors are located in the endothelial linings of most organs like the brain, heart, lungs, kidneys, intestine, liver, and pancreas, among others. The main function of the ACE2 receptors is binding to specific target molecules to maintain the renin-angiotensin system that is crucial for regulating dilation of blood vessels, as well as maintain blood glucose levels, the immune system, and homeostasis.

Therefore, SARS-CoV-2 binding to these ACE2 receptors facilitates the entry of this virus into all the organs that have these receptors, thus leading to the ability of SARS-CoV-2 to cause widespread damage in the body. Upon entry into the pancreas, for example, SARS-CoV-2 can inhibit ß-cells function, which worsens hyperglycemia and increases the risk for acute diabetic complications.

Similarly, the presence of ACE2 receptors in brain tissues may cause invasion into the pituitary gland and lead to pituitary apoplexy. The entry of SARS-CoV-2 into the brain can also cause neurological damage in infected patients, which may account for some of the common neurological complaints of COVID-19 including headaches, confusion, dysgeusia, anosmia, nausea, and vomiting.

Study findings

Hypopituitarism leading to metabolic syndrome has been scientifically linked to higher mortality in COVID-19 patients. In fact, the presence of a single metabolic syndrome component has been observed to double the risk of death by COVID-19. This risk was even higher among patients with DM and hypertension.

There was also an increased incidence of VFs in COVID-19 patients with hypopituitarism. Hence, patients with DM, obesity, hypertension, and chronic inflammatory disease, are all at an increased risk of poor outcomes and death in COVID-19.

Arterial hypertension is a common finding in adults with GHD, which is another consequence of hypopituitarism. Hypopituitarism also causes adrenal insufficiency, a condition that is primarily managed with glucocorticoids and hormonal replacement therapies.

Notably, patients with COVID-19 are often treated for prolonged periods with high-dose exogenous glucocorticoids, which is a class of steroids that suppress some activities of the immune system. This treatment approach may result in suppression of the hypothalamic-pituitary–adrenal axis that can lead to adrenal insufficiency.

Hypogonadism is another aspect of pituitary insufficiency that predisposes patients, especially males, to COVID-19. Evidence shows that males with hypogonadism were more frequently affected by metabolic syndrome.

Pituitary apoplexy, albeit rare, has also been linked to COVID-19, especially in patients with pituitary adenomas and those who are being treated with anticoagulant therapy. This may be because the pituitary gland becomes overstimulated during an infectious disease, which may increase pituitary blood demand and lead to sudden infarction precipitating acute apoplexy.

This phenomenon has also been shown in patients suffering from infectious diseases that cause hemorrhagic fevers. Taken together, pituitary apoplexy complicates treatment and management procedures in COVID-19 patients.

Despite the use of steroids in COVID-19 patients, there have been no contraindications for vaccination in such patients. However, those on extensive hormonal therapies need constant monitoring for best results.

Implications

The pituitary gland acts like a double-edged sword for COVID-19. On one end, hypopituitarism predisposes patients to metabolic disorders like DM, obesity, and VFs, all of which are known risk factors for COVID-19.

On the other hand, COVID-19 may cause direct or indirect damage to the pituitary glands by entering the brain and inducing unfavorable vascular events – though evidence on this remains lesser in comparison to that of hypopituitarism. Ultimately, the researchers of the current study conclude that managing patients with hormonal insufficiencies optimally with steroids is likely to improve outcomes in severe COVID-19.

Journal reference:

COVID-19 May Be Severe in Cushing’s Patients

A young healthcare worker who contracted COVID-19 shortly after being diagnosed with Cushing’s disease was detailed in a case report from Japan.

While the woman was successfully treated for both conditions, Cushing’s may worsen a COVID-19 infection. Prompt treatment and multidisciplinary care is required for Cushing’s patients who get COVID-19, its researchers said.

The report, “Successful management of a patient with active Cushing’s disease complicated with coronavirus disease 2019 (COVID-19) pneumonia,” was published in Endocrine Journal.

Cushing’s disease is caused by a tumor on the pituitary gland, which results in abnormally high levels of the stress hormone cortisol (hypercortisolism). Since COVID-19 is still a fairly new disease, and Cushing’s is rare, there is scant data on how COVID-19 tends to affect Cushing’s patients.

In the report, researchers described the case of a 27-year-old Japanese female healthcare worker with active Cushing’s disease who contracted COVID-19.

The patient had a six-year-long history of amenorrhea (missed periods) and dyslipidemia (abnormal fat levels in the body). She had also experienced weight gain, a rounding face, and acne.

After transferring to a new workplace, the woman visited a new gynecologist, who checked her hormonal status. Abnormal findings prompted a visit to the endocrinology department.

Clinical examination revealed features indicative of Cushing’s syndrome, such as a round face with acne, central obesity, and buffalo hump. Laboratory testing confirmed hypercortisolism, and MRI revealed a tumor in the patient’s pituitary gland.

She was scheduled for surgery to remove the tumor, and treated with metyrapone, a medication that can decrease cortisol production in the body. Shortly thereafter, she had close contact with a patient she was helping to care for, who was infected with COVID-19 but not yet diagnosed.

A few days later, the woman experienced a fever, nausea, and headache. These persisted for a few days, and then she started having difficulty breathing. Imaging of her lungs revealed a fluid buildup (pneumonia), and a test for SARS-CoV-2 — the virus that causes COVID-19 — came back positive.

A week after symptoms developed, the patient required supplemental oxygen. Her condition worsened 10 days later, and laboratory tests were indicative of increased inflammation.

To control the patient’s Cushing’s disease, she was treated with increasing doses of metyrapone and similar medications to decrease cortisol production; she was also administered cortisol — this “block and replace” approach aims to maintain cortisol levels within the normal range.

The patient experienced metyrapone side effects that included stomach upset, nausea, dizziness, swelling, increased acne, and hypokalemia (low potassium levels).

She was given antiviral therapies (e.g., favipiravir) to help manage the COVID-19. Additional medications to prevent opportunistic fungal infections were also administered.

From the next day onward, her symptoms eased, and the woman was eventually discharged from the hospital. A month after being discharged, she tested negative for SARS-CoV-2.

Surgery for the pituitary tumor was then again possible. Appropriate safeguards were put in place to protect the medical team caring for her from infection, during and after the surgery.

The patient didn’t have any noteworthy complications from the surgery, and her cortisol levels soon dropped to within normal limits. She was considered to be in remission.

Although broad conclusions cannot be reliably drawn from a single case, the researchers suggested that the patient’s underlying Cushing’s disease may have made her more susceptible to severe pneumonia due to COVID-19.

“Since hypercortisolism due to active Cushing’s disease may enhance the severity of COVID-19 infection, it is necessary to provide appropriate, multidisciplinary and prompt treatment,” the researchers wrote.

From https://cushingsdiseasenews.com/2021/01/15/covid-19-may-be-severe-cushings-patients-case-report-suggests/?cn-reloaded=1

Transsphenoidal Surgery Is Safe and Effective Treatment for Cushing’s Disease

Transsphenoidal surgery, a minimally invasive surgery to remove tumors in the pituitary gland, is safe and effective to treat Cushing’s disease, a 20-year history of cases in a Belgian hospital shows.

The surgery resulted in high remission rates (83%) in patients. It was also found to be safe, rarely leading to insufficient functioning of the pituitary gland.

The study, “Outcome of transsphenoidal surgery for Cushing’s Disease: a single-center experience over 20 years,” was published in the journal World Neurosurgery.

Surgical removal of tumors in the pituitary gland of the brain remains the gold standard for Cushing’s disease treatment.

Transsphenoidal surgery (TSS) usually leads to good remission rates ranging from 68-95%, depending on the location and type of tumor, the neurosurgeon’s expertise, follow-up period, and the definition of remission.

Today, TSS consists of surgery directed through the nose to get to the bottom of the skull, where the pituitary gland is located. The tumor is reached via the nasal cavity with no need for incisions on the face.

To address the safety and effectiveness of this type of surgery for treating Cushing’s, researchers retrospectively reviewed the outcome of 71 patients who received their first TSS at Saint-Luc Hospital, Belgium, between 1996 and 2017. Patients were followed for an average of 6.8 years (82 months).

Surgeons used a type of TSS that is image-guided with the help of a microscope which magnifies the surgeon’s vision.

Remission was defined as normal fasting cortisol level, normal 24-hour urinary-free cortisol, or prolonged need for hydrocortisone replacement for one year after surgery.

Replacement therapies are sometimes needed when the pituitary is not producing enough cortisol after surgery.

Patients were mostly women, ages 15 to 84. Some of them, 32%, required multiple surgeries.

In total, 46 patients out of 71 were in remission after the first surgery, 11 after the second surgery, one after the third, and one after the fourth intervention.

A successful first surgery, resulting in a one-year remission, was a positive indicator for patients, as it was associated with high final remission rates (95%).

However, if the first surgery failed, only 36% of patients achieved a final remission.

“Obtaining a lasting remission after a first TSS could be an interesting parameter to influence future therapeutic decisions [like] performing repeated surgery rather than choosing second-line therapies,” researchers wrote.

Overall, remission was achieved in 83% of patients who underwent a single or multiple TSS intervention, a recurrence rate comparable to previous reports.

Surgery was particularly successful for curing patients with macroadenomas — tumors larger than 10 mm — leading to a 92% remission rate.

Small tumors that were not visible on magnetic resonance imaging (MRI) scans were more difficult to treat, with only 71% of patients being cured. Still, such a remission rate was better than what is commonly reported for MRI-negative tumors. This is likely explained by a higher level of expertise by the surgeon.

Levels of cortisol one day after TSS were significantly lower in patients with long-term remission. However, high levels were still observed in a few patients, especially those who had Cushing’s disease for many years.

“Therefore, high cortisol levels in the postoperative early days do not always indicate persistent disease and later [cortisol] evaluation is warranted,” the researchers wrote.

Most complications from surgery were minor and transient, except for seven patients who developed diabetes. Only 8.8% of patients developed long-term failure of the pituitary gland, likely because physicians favored a less aggressive intervention plan to leave the pituitary gland as intact as possible.

However, such an approach may also explain why some patients had to undergo multiple surgeries to completely remove the tumor.

In addition, a longer duration of Cushing’s disease symptoms and higher cortisol levels before surgery could significantly predict a poorer likelihood of being cured by TSS.

“Neuronavigation-guided microscopic TSS is a safe and effective primary treatment for [Cushing’s disease], allowing high remission rates,” the researchers wrote.

From https://cushingsdiseasenews.com/2018/07/26/transsphenoidal-surgery-safe-effective-treatment-cushings-disease/

Oral Test for Adult Growth Hormone Deficiency Approved in US

The US Food and Drug Administration (FDA) has approved an orally available ghrelin agonist, macimorelin (Macrilen, Aeterna Zentaris), to be used in the diagnosis of patients with adult growth-hormone deficiency (AGHD).

Macimorelin stimulates the secretion of growth hormone from the pituitary gland into the circulatory system. Stimulated growth-hormone levels are measured in four blood samples over 90 minutes after oral administration of the agent for the assessment of growth-hormone deficiency.

Prior to the approval of macimorelin, the historical gold standard for evaluation of adult growth-hormone deficiency was the insulin tolerance test (ITT), an intravenous test requiring many blood draws over several hours.

The ITT procedure is inconvenient for patients and medical practitioners and is contraindicated in some patients, such as those with coronary heart disease or seizure disorder, because it requires the patient to experience hypoglycemia to obtain an accurate result.

Adult growth-hormone deficiency is a rare disorder characterized by the inadequate secretion of growth hormone from the pituitary gland. It can be hereditary; acquired as a result of trauma, infection, radiation therapy, or brain tumor growth; or can even emerge without a diagnosable cause. Currently, it is treated with once-daily injections of subcutaneous growth hormone.

“Clinical studies have demonstrated that growth-hormone stimulation testing for adult growth-hormone deficiency with oral…macimorelin is reliable, well-tolerated, reproducible, and safe and a much simpler test to conduct than currently available options,” said Kevin Yuen, MD, clinical investigator and neuroendocrinologist, Barrow Neurological Institute, and medical director of the Barrow Neuroendocrinology Clinic, Phoenix, Arizona, in a press release issued by Aeterna Zentaris.

“The availability of…macimorelin will greatly relieve the burden of endocrinologists in reliably and accurately diagnosing adult growth-hormone deficiency,” he added.

Aeterna Zentaris estimates that approximately 60,000 tests for suspected adult growth-hormone deficiency are conducted each year across the United States, Canada, and Europe.

“In the absence of an FDA-approved diagnostic test for adult growth-hormone deficiency, Macrilen fills an important gap and addresses a medical need for a convenient test that will better serve patients and health providers,” said Michael V Ward, chief executive officer, Aeterna Zentaris.

Macrilen is expected to be launched in the United States during the first quarter of 2018.

It is also awaiting approval in the European Union.

Follow Lisa Nainggolan on Twitter: @lisanainggolan1. For more diabetes and endocrinology news, follow us on Twitter and on Facebook.

From https://www.medscape.com/viewarticle/890457

Increase in Glucose Uptake by Cushing’s Disease-associated Tumors Could Improve Early Detection

An increase in glucose uptake by Cushing’s disease-associated pituitary tumors could improve their detection, new research shows.

The study, “Corticotropin releasing hormone can selectively stimulate glucose uptake in corticotropinoma via glucose transporter 1,” appeared in the journal Molecular and Cellular Endocrinology.

The study’s senior author was Dr. Prashant Chittiboina, MD, from the Department of Neurosurgery, Wexner Medical Center, The Ohio State University, in Columbus, Ohio.

Microadenomas – tumors in the pituitary gland measuring less than 10 mm in diameter – that release corticotropin, or corticotropinomas, can lead to Cushing’s disease. The presurgical detection of these microadenomas could improve surgical outcomes in patients with Cushing’s.

But current tumor visualization methodologies – magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) – failed to detect a significant percentage of pituitary microadenomas.

Stimulation with corticotropin-releasing hormone (CRH), which increases glucose uptake, has been suggested as a method of increasing the detection of adenomas with 18F-FDG PET, by augmenting the uptake of 18F-FDG – a glucose analog.

However, previous studies aiming to validate this idea have failed, leading the research team to hypothesize that it may be due to a delayed elevation in glucose uptake in corticotropinomas.

The scientists used clinical data to determine the effectiveness of CRH in improving the detection of corticotropinomas with 18F-FDG PET in Cushing’s disease.

They found that CRH increased glucose uptake in human and mouse tumor cells, but not in healthy mouse or human pituitary cells that produce the adrenocorticotropic hormone (ACTH). Exposure to CRH increased glucose uptake in mouse tumor cells, with a maximal effect at four hours after stimulation.

Similarly, the glucose transporter GLUT1, which is located at the cell membrane, was increased two hours after stimulation, as was GLUT1-mediated glucose transport.

These findings indicate a potential mechanism linking CRH exposure to augmented glucose uptake through GLUT1. Expectedly, the inhibition of glucose transport with fasentin suppressed glucose uptake.

The researchers consistently observed exaggerated evidence of GLUT1 in human corticotropinomas. In addition, human corticotroph tumor cells showed an increased breakdown of glucose, which indicates that, unlike healthy cells, pituitary adenomas use glucose as their primary source of energy.

Overall, the study shows that corticotropin-releasing hormone (CRH) leads to a specific and delayed increase in glucose uptake in tumor corticotrophs.

“Taken together, these novel findings support the potential use of delayed 18F-FDG PET imaging following CRH stimulation to improve microadenoma detection in [Cushing’s disease],” researchers wrote. The scientists are now conducting a clinical trial to further explore this promising finding.

From https://cushingsdiseasenews.com/2017/10/12/glucose-uptake-in-cushings-disease-could-improve-presurgical-tumor-detection/

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