SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Zona fasciculata

23

Obesity is a chronic, relapsing medical condition that results from an imbalance of energy expenditure and consumption. It is a leading cause of preventable illness, disability and premature death. The causes of obesity are multifactorial and include behavioural, socioeconomic, genetic, environmental and psychosocial factors. Rarely are endocrine diseases, e.g., hypothyroidism or Cushing’s syndrome, the cause of obesity. What is less understood is how obesity affects the endocrine system. In this review, we will discuss the impact of obesity on multiple endocrine systems, including the hypothalamic-pituitary axis, changes in vitamin D homeostasis, gender steroids and thyroid hormones. We will also examine the renin angiotensin aldosterone system and insulin pathophysiology associated with obesity. We will provide a general overview of the biochemical changes that can be seen in patients with obesity, review possible aetiologies of these changes and briefly consider current guidelines on their management. This review will not discuss endocrine causes of obesity.

Concepts: Kidney, Pancreas, Endocrinology, Thyroid, Renin-angiotensin system, Endocrine system, Adrenal cortex, Zona fasciculata

6

In a 10-week proof-of-concept study (LINC 1), the potent oral 11β-hydroxylase inhibitor osilodrostat (LCI699) normalized urinary free cortisol (UFC) in 11/12 patients with Cushing’s disease. The current 22-week study (LINC 2; NCT01331239) further evaluated osilodrostat in patients with Cushing’s disease.

Concepts: Hypertension, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Zona fasciculata

3

Type 2 Diabetes (T2D) and Cushing’s syndrome (CS) share clinical characteristics and several small studies have recorded a high prevalence of hypercortisolism in T2D, which could have therapeutic implications. We aimed to assess the prevalence of endogenous hypercortisolism in T2D patients.

Concepts: Medicine, Hypertension, Diabetes mellitus type 2, Diabetes mellitus, Obesity, Cushing's syndrome, Polyuria, Zona fasciculata

2

Hair cortisol evaluation has been used to help detect patients with suspected Cushing syndrome. Our goal was to correlate segmental hair cortisol with biochemical testing in patients with Cushing syndrome and controls. This study was a prospective analysis of hair cortisol in confirmed Cushing syndrome cases over 16 months.

Concepts: Hypertension, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Zona fasciculata

2

Incidental discovery of adrenal masses has increased over the past few years. Mild alterations in cortisol secretion without clinical signs of overt hypercortisolism (subclinical Cushing’s syndrome) are a common finding in patients with these tumours. Although metabolic alterations and increased cardiovascular risk have been noted in patients with subclinical Cushing’s syndrome, incidence of cardiovascular events and mortality in the long term have not been assessed. We aimed to ascertain the frequency of new cardiovascular events and mortality in patients with non-secreting adrenal incidentalomas, tumours of intermediate phenotype, or those causing subclinical Cushing’s syndrome.

Concepts: Osteoporosis, Hypertension, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Incidentaloma, Zona fasciculata

1

Primary adrenal Cushing syndrome is the result of cortisol hypersecretion mainly by adenomas and, rarely, by bilateral micronodular or macronodular adrenocortical hyperplasia. cAMP-dependent protein kinase A (PKA) signalling is the major activator of cortisol secretion in the adrenal cortex. Many adenomas and hyperplasias associated with primary hypercortisolism carry somatic or germline mutations in genes that encode constituents of the cAMP-PKA pathway. In this Review, we discuss Cushing syndrome and its linkage to dysregulated cAMP-PKA signalling, with a focus on genetic findings in the past few years. In addition, we discuss the presence of germline inactivating mutations in ARMC5 in patients with primary bilateral macronodular adrenocortical hyperplasia. This finding has implications for genetic counselling of affected patients; hitherto, most patients with this form of adrenal hyperplasia and Cushing syndrome were thought to have a sporadic and not a familial disorder.

Concepts: Hypertension, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Adrenocorticotropic hormone, Adrenal cortex, Zona fasciculata

1

Endogenous pathologic hypercortisolism, or Cushing’s syndrome, is associated with poor quality of life, morbidity and increased mortality. Early diagnosis may mitigate against this natural history of the disorder. The clinical presentation of Cushing’s syndrome varies, in part related to the extent and duration of cortisol excess. When hypercortisolism is severe, its signs and symptoms are unmistakable. However, most of the signs and symptoms of Cushing’s syndrome are common in the general population (e.g. hypertension and weight gain) and not all are present in every patient. In addition to classical features of glucocorticoid excess, such as proximal muscle weakness and wide purple striae, patients may present with the associated co-morbidities that are caused by hypercortisolism. These include cardiovascular disease, thromboembolic disease, psychiatric and cognitive deficits, and infections. As a result, internists and generalists must consider Cushing’s syndrome as a cause, and endocrinologists should search for and treat these co-morbidities. Recommended tests to screen for Cushing’s syndrome include 1 mg dexamethasone suppression, urine free cortisol and late night salivary cortisol. These may be slightly elevated in patients with physiologic hypercortisolism, which should be excluded, along with exogenous glucocorticoid use. Each screening test has caveats and the choice of tests should be individualized based on each patient’s characteristics and lifestyle. The objective of this review was to update the readership on the clinical and biochemical features of Cushing’s syndrome that are useful when evaluating patients for this diagnosis.

Concepts: Hypertension, Diabetes mellitus, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Dexamethasone suppression test, Zona fasciculata

1

Cushing’s disease is a rare disorder characterized by overproduction of ACTH from a pituitary adenoma leading to hypercortisolemia that in turn leads to increased morbidity and mortality.

Concepts: Hypertension, Pituitary adenoma, Corticosteroid, Glucocorticoid, Cortisol, Cushing's syndrome, Adrenocorticotropic hormone, Zona fasciculata

0

The adrenocortical gland undergoes structural and functional remodelling in the fetal and postnatal periods. After birth, the fetal zone of the gland undergoes rapid involution in favor of the definitive cortex, which reaches maturity with the emergence of the zona reticularis(zR) at the adrenarche. The mechanisms underlying the adrenarche, the process leading to pre-puberty elevation of plasma androgens in higher primates, remain unknown, largely due to lack of any experimental model. By following up fetal and definitive cortex cell lines in mice, we showed that activation of protein kinase A (PKA) signaling mainly impacts the adult cortex by stimulating centripetal regeneration, with differentiation and then conversion of the zona fasciculata into a functional zR. Animals developed Cushing syndrome associated with primary hyperaldosteronism, suggesting possible coexistence of these hypersecretions in certain patients. Remarkably, all of these traits were sex-dependent: testicular androgens promoted WNT signaling antagonism on PKA, slowing cortical renewal and delaying onset of Cushing syndrome and the establishment of the zR in male mice, this being corrected by orchidectomy. In conclusion, zR derives from centripetal conversion of the zona fasciculata under cellular renewal induced by PKA signaling, determining the size of the adult cortex. Finally, we demonstrated that this PKA-dependent mobilization of cortical progenitors is sexually dimorphic and could, if confirmed in humans, account for female preponderance in adrenocortical pathologies.

Concepts: Hypertension, Cortisol, Endocrine system, Cushing's syndrome, Adrenal cortex, Mice, Glands, Zona fasciculata

0

The aim of this study was to determine the frequency of central thyroid dysfunctions in Cushing’s syndrome (CS). We also aimed to evaluate the frequency of hyperthyroidism due to the syndrome of the inappropriate secretion of TSH (SITSH), which was recently defined in patients with insufficient hydrocortisone replacement after surgery.

Concepts: Hypertension, Corticosteroid, Glucocorticoid, Cortisol, Thyroid hormone, Cushing's syndrome, Polyuria, Zona fasciculata