Frequently Asked Questions in Patients With Adrenal Insufficiency in the Time of COVID-19

Adrenal insufficiency (AI) is a life-threatening disorder, with increased morbidity and mortality, especially in case of an acute illness that can increase the requirement of cortisol. A novel infectious disease, termed Coronavirus Disease 2019 (COVID-19), appeared in 2020. Therefore, AI patients are experiencing a novel challenge: the risk of infection. In our experience, a prompt contact to the Endocrine center (with a telemedicine consultation) and a full awareness of diseases (cortisol deficiency, COVID-19 and the self-management of an adrenal crisis) are important to motivate patients. Vaccine is an effective treatment to prevent hospitalization and aggressive course of COVID-19. Some patients manifest challenges due to inequitable access and vaccine hesitancy, resulting in a delay in the acceptance of vaccines despite the availability of vaccination services. Therefore, an effort of all physicians must be conducted in order to advise patients with AI. In this short review, we try to answer some frequently asked questions regarding the management of patients with AI.

Rathke’s Cyst and Adrenal Insufficiency: A Rare Case of Hyponatremia

Background: Hyponatremia is the most common electrolyte abnormality encountered in clinical practice, the diagnosis of which can be challenging. A holistic approach with appropriate investigations is imperative to its diagnosis and management. We report this peculiar case of a patient with hypopituitarism secondary to Rathke’s cyst resulting in secondary Adrenal Insufficiency, thus causing Hyponatremia. Case Details: A 32 year male was admitted to hospital with an intractable headache and deterioration in his general wellbeing. His admission parameters revealed a GCS of 15 with normal observations. He had no evidence of meningism and examination of all other systems was unremarkable. He was not on any regular medications and there was no history of trauma. Bloods revealed a Sodium of 122mmol/l, the rest being normal. Investigations including a CT brain, CXR, paired serum & urine osmolality, urinary sodium, Thyroid functions and a 9am cortisol were conducted. Radiological imaging was unremarkable. Subsequently, he was fluid restricted due to a euvolemic fluid status. Serum osmolality was 246 mmol/kg (275-295 mmol/kg), Urine osmolality 847 mmol/kg, urine sodium 85 mmol/l and a 9 am serum cortisol of 29 nmol/L, in keeping with Adrenal Insufficiency. A further decline in his Sodium to 116 mmol/L resulted in Hyponatremic Encephalopathy. In view of impending Adrenal crisis, IV hydrocortisone was commenced in conjunction with hypertonic Saline. This was followed by strict monitoring with cautious correction. An anterior Pituitary profile, serum testosterone and Prolactin were requested. Serum Testosterone levels were 0.4nmol/L (10.0-36nmol/L), FSH- 2.5 IU/L (1.0-11.0 IU/L) and LH- 1.9 IU/L (1.5-9.3 IU/L). Serum prolactin was 85mU/L (45-375 mU/L), TSH- 0.59 mU/L (0.30-6.00 mU/L), Free T4- 13.0 pmol/L (10.4-24.5 pmol/L), IGF1-135 ug/L (60-197 ug/L). This was suggestive of partial hypopituitarism. An MRI Pituitary revealed appearances in keeping with a Rathke’s cyst occupying the pituitary fossa without compromise of the Optic Chiasma. Once stable, he was safely discharged with follow-up appointments planned with the Endocrine and Neurosurgical teams. Discussion: Rathke cleft cysts are non-neoplastic cysts arising from the embryological remnants of Rathke’s pouch in the pituitary gland. Hormonal and visual manifestations can occur if these cysts enlarge and interfere with the Pituitary production and optic chiasma. A proposed mechanism causing Hyponatremia in the context of Cortisol deficiency is increased hypothalamic secretion of Corticotropin releasing hormone (CRH), a Vasopressin secretagogue. Cortisol feeds back negatively on CRH, which is removed with adrenal insufficiency. Hyponatremia is thus often seen in patients with adrenal insufficiency, caused by an inappropriate increase in vasopressin due to cortisol deficiency and inability to excrete free water.

New onset adrenal insufficiency in a patient with COVID-19

SARS-CoV-2 is the cause of COVID-19. Since the outbreak and rapid spread of COVID-19, it has been apparent that the disease is having multi-organ system involvement. Still its effect in the endocrine system is not fully clear and data on cortisol dynamics in patients with COVID-19 are not yet available. SARS-CoV-2 can knock down the host’s cortisol stress response. Here we present a case of a 51-year-old man vomiting for 10 days after having confirmed COVID-19 infection. He had hypotension and significant hyponatraemia. Work-up was done including adrenocorticotropic hormone stimulation test. He was diagnosed as suffering from adrenal insufficiency and started on steroids with subsequent improvement in both blood pressure and sodium level. COVID-19 can cause adrenal insufficiency. Clinicians must be vigilant about the possibility of an underlying relative cortisol deficiency in patients with COVID-19.

GDF15 Is Elevated in Conditions of Glucocorticoid Deficiency and Is Modulated by Glucocorticoid Replacement

Context GDF15 is a stress-induced hormone acting in the hindbrain that activates neural circuitry involved in establishing aversive responses and reducing food intake and body weight in animal models. Anorexia, weight loss, nausea and vomiting are common manifestations of glucocorticoid deficiency, and we hypothesized that glucocorticoid deficiency may be associated with elevated levels of GDF15. Objective To determine the impact of primary adrenal insufficiency (PAI) and glucocorticoid replacement on circulating GDF15 levels. Methods and Results We measured circulating concentrations of GDF15 in a cohort of healthy volunteers and Addison’s disease patients following steroid withdrawal. Significantly higher GDF15 (mean ± standard deviation [SD]) was observed in the Addison’s cohort, 739.1 ± 225.8 pg/mL compared to healthy controls, 497.9 ± 167.7 pg/mL (P = 0.01). The effect of hydrocortisone replacement on GDF15 was assessed in 3 independent PAI cohorts with classical congenital adrenal hyperplasia or Addison’s disease; intravenous hydrocortisone replacement reduced GDF15 in all groups. We examined the response of GDF15 to increasing doses of glucocorticoid replacement in healthy volunteers with pharmacologically mediated cortisol deficiency. A dose-dependent difference in GDF15 (mean ± SD) was observed between the groups with values of 491.0 ± 157.7 pg/mL, 427.0 ± 152.1 pg/mL and 360 ± 143.1 pg/mL, in the low, medium and high glucocorticoid replacement groups, respectively, P < .0001. Conclusions GDF15 is increased in states of glucocorticoid deficiency and restored by glucocorticoid replacement. Given the site of action of GDF15 in the hindbrain and its effects on appetite, further study is required to determine the effect of GDF15 in mediating the anorexia and nausea that is a common feature of glucocorticoid deficiency.

ACTH signalling and adrenal development: lessons from mouse models

The melanocortin-2-receptor (MC2R), also known as the ACTH receptor, is a critical component of the hypothalamic–pituitary–adrenal axis. The importance of MC2R in adrenal physiology is exemplified by the condition familial glucocorticoid deficiency (FGD), a potentially fatal disease characterised by isolated cortisol deficiency. MC2R mutations cause ~25% of cases. The discovery of a MC2R accessory protein MRAP, mutations of which account for ~20% of FGD, has provided insight into MC2R trafficking and signalling. MRAP is a single transmembrane domain accessory protein highly expressed in the adrenal gland and essential for MC2R expression and function. Mouse models helped elucidate the action of ACTH. The Mc2r-knockout (Mc2r − / − ) mice was the first mouse model developed to have adrenal insufficiency with deficiencies in glucocorticoid, mineralocorticoid and catecholamines. We recently reported the generation of the Mrap − / − mice which better mimics the human FGD phenotype with isolated glucocorticoid deficiency alone. The adrenal glands of adult Mrap − / − mice were grossly dysmorphic with a thickened capsule, deranged zonation and deranged WNT4/beta-catenin and sonic hedgehog (SHH) pathway signalling. Collectively, these mouse models of FGD highlight the importance of ACTH and MRAP in adrenal progenitor cell regulation, cortex maintenance and zonation.

Glucocorticoid Activity of Adrenal Steroid Precursors in Untreated Patients With Congenital Adrenal Hyperplasia

Context and Objective We describe the clinical features and biochemical characteristics of a unique population of severely affected untreated patients with congenital adrenal hyperplasia (CAH) from an Indonesian population with proven cortisol deficiency but without clinical signs of cortisol deficiency. We evaluated the in vitro glucocorticoid activity of all relevant adrenal steroid precursors occurring in patients with CAH. Design Cross-sectional cohort study and translational research. Intervention/Main Outcome Measures Adrenal steroid precursor concentrations before and 60 minutes after ACTH administration to 24 untreated patients with CAH (3 to 46 years) with proven cortisol deficiency (<500 nmol/L post-ACTH) measured by liquid chromatography–tandem mass spectrometry were compared with six control patients (Mann-Whitney U test). Glucocorticoid receptor (GR) activation was determined by dual-luciferase assays in human embryonic kidney cells transfected with the GR and exposed to increasing amounts of adrenal steroid precursors for 24 hours. Results Blood concentrations of the steroid precursors 11-deoxycortisol (457 nmol/L, P = 0.003), 11-deoxycorticosterone (55 nmol/L, P = 0.003), 17-hydroxyprogesterone (610 nmol/L, P < 0.001), progesterone (29 nmol/L, P < 0.001), and 21-deoxycortisol (73 nmol/L) were strongly elevated compared with control subjects. The GR was activated with comparable potency to cortisol by corticosterone and 21-deoxycortisol or with 4 to 100 times lower potency by 11-hydroxyprogesterone, 11-deoxycortisol, aldosterone, 11-deoxycorticosterone, progesterone, and 17-hydroxyprogesterone. Conclusions We identified strongly elevated adrenal steroid precursor concentrations in blood from untreated patients with CAH and demonstrated glucocorticoid activity of these adrenal precursors in vitro, suggesting a possible role of these precursors in the clinical phenotype of these patients. Further studies are necessary to evaluate the role of these precursors in more detail.