Hyperfunction of adrenal gland - cushing's and conn's syndrome Flashcards
What are the endocrine causes of hypertension
primary hyperaldosteronism
Phaeochromacytoma
Cushing’s syndrome
Acromegaly
Hyperparathyroidism
Hypothyroidism
What is primary hyperaldosteronism
Adrenal gland produces excess aldosterone (zona glomerulosa)
What is phaeochromocytoma
Excess catecholamines being produced by the adrenal cortex
What is Cushing’s syndrome
Excess corticosteroids being produced by the adrenal gland
What is Conn’s syndrome
Production of excess aldosterone
What happens in Cushing’s syndrome and what does it cause in the body
Excess corticosteroids - causes tissue breakdown
sodium retention
Insulin antagonism
What are the side effects of glucocorticoid therapy
Increased severity and frequency of infection
Muscle wastage due to cortisol being catabolic
Loss of fat stores due to function of excess cortisol
What are the signs of Cushing’s syndrome that are seen on examination
buffalo hump on back
Cardiac failure
Diabetes
Oedema
Moon face
Atrophy of muscle and replaced with fat
Thin hands and feet
Bruising
Thin skin ulcers
What is the main cause of an ACTH dependant Cushing’s syndrome
Pituitary tumour
What is the main cause of an ACTH-independant Cushing’s syndrome
Adrenal tumour
What does high CRH, ACTH levels and Cortisol levels mean the site of pathology in the Cushing’s syndrome is
Hypothalamus pathology
What does Low CRH, High ACTH and Cortisol mean the site of pathology in the Cushing’s syndrome is
Anterior pituitary pathology
What does low CRH and ACTH with high cortisol mean the site of pathology in the Cushing’s syndrome is
The adrenal cortex
What is used to check for hypercortisolism
Overnight dexamethasone test - patient given dexamethasone in the night and their cortisol is measured in the morning
What is normal 24 hr urinary free cortiso
14-135 nmol/day
What is the normal 1mg overnight dexamethasone suppression test urinary cortisol
less than 50 nanomol at 9am
What is ectopic ACTH
ACTH that is produced outside the pituitary gland
What is the treatment for tumour causing Cushing’s
Adrenal hormone synthesis inhibitors - ketoconazole and metyrapone
Destroy adrenocortical cells - mitotane
Radiotherapy or a bilateral adrenalectomy
What is the difference between cushing’s syndrome and disease
Cushing’s disease is caused by excess ACTH caused by a pituitary adenoma which drives hypersecretion of adrenal gland
How does aldosterone carry out it’s effect
Acts on the renal tubules, increasing sodium reabsorption and potassium excretion
What is the screening test to check for Conn’s syndrome (hyperaldosteronism)
PA/PPR - aldosterone to renin ration
what does a PA/PRA of more than 20 mean
ratio of aldosterone to renin over 20 mens primary hyperaldosteronism
What does a PA/PRA less than 20 mean
Ratio of aldosterone to renin less than 20 means secondary hyperaldosteronism
