Adrenal Gland- clinical aspects Flashcards
RECAP- which hormone does the zona glomerulosa produce?
Aldosterone
RECAP- which hormone does the zona fasciculata produce?
Cortisol
RECAP- which hormone does the zona reticularis produce?
Testosterone
RECAP- which hormones does the adrenal cortex produce?
Norepinephrine
Epinephrine
What is the role of aldpsterone?
Water-salt balance
Helps absorb water
What is the role of cortisol?
Helps with energy balance and maintains glucose levels
Counter-regulatory for BG levels, opposite of insulin basically
How are hormones, like cortisol, produced from cholesterol?
Cholesterol converted to progesterone.
221-hydroxylase leads to formation of cortisol
Long term use of which type of drug can cause adrenal suppression?
Steroids
Which marker is usually present in the majority of cases of autoimmune Addison’s disorder?
Adrenal autoanitbodies
What is the pathology behind Addison’s disease?
Autoimmune destruction causing an infiltration of lymphocytes into the adrenal cortex
Like other autoimmune conditions, if you have Addison’s you are more likely to have another autoimmune related problem.
What are some of the likely autoimmune conditions associated with Addison’s?
Thyroid disease
Type 1 diabetes
Premature ovarian failure
List some of the symptoms of primary adrenal failure.
Weakness, fatigue, weight loss.
Skin pigmentation
Hypotension
Unexplained vomiting or diarrhoea
Salt craving
Postural symptoms
What are some possible clues that point towards adrenal failure?
Disproportion between severity of illness and circulatory collapse/hypotension/dehydration.
Unexplained hypoglycaemia
Previous depression or weight loss
Which investigations can be carried out to assist in the diagnosis of adrenal insufficiency?
Routine bloods- U&E, glucose, FBC
Random cortisol
Synacthen test/ rapid ACTH stimulation test
In the U&E blood test in someone with adrenal insufficiency, what is a classical pattern?
High potassium and low sodium
If carrying out a random cortisol test and it is >450nmol/L, what is it likely NOT to be?
Addison’s
When is the best time to do a random cortisol test?
Early in the morning or when the patient is presenting with an extreme illness
If the Synacthen test is abnormal and suggestive of adrenal insufficiency, which further test is carried out?
Plasma ACTH
In testing plasma ACTH, if levels are elevated, what does this tell us about the adrenal insufficiency?
It is primary adrenocortical insufficiency
In testing plasma ACTH, if levels are supressed, what does this tell us about the adrenal insufficiency?
Secondary adrenocortical insufficiency
What is the treatment for someone with adrenocortical insufficiency?
Glucocorticoid replacement as these steroid hormones are essential for life
->most likely hydrocortisone
What do patients on steroids need to have on them?
Some form of identification at all time in case they come in unconscious or are steroid dependant
What happens to the amount of steroids produced by the body when under stress?
Amount of steroids produced increases
If a patient is on long-term steroids, what happens if they are under stress or illness?
Body cannot produced adequate steroids itself to respond so patient needs to increase their steroid dose
What are three rules for patients on steroid?
- Never miss a dose
- Double the hydrocortisone dose in event of intercurrent illness, like flu, UTI
- If severe diarrhoea or vomiting, get help straight away
How is blood pressure linked to hyperfunction of the adrenal gland?
Causes hypertension
Hyperaldosteronism?
Condition is which the body produces too much aldosterone
RECAP- Cushing’s syndrome?
Excess corticosteroids produced by the body
Which gland produces too many aldosterone hormones in Cushing’s syndrome?
Adrenal gland
RECAP- is cortisol a catabolic or anabolic hormone?
Catabolic
What are the roles of cortisol?
-Tissue breakdown
-Sodium retention
-Insulin antagonism
What happens as a result of the catabolic nature pf cortisol when breaking down tissues?
Causes weakness of the sin, muscle and bone
What happens as a result of too much cortisol regarding sodium retention?
May cause hypertension and heart failure
What can happen if there is too much cortisol in regards to diabetes?
More likely to cause diabetes as cortisol is an insulin antagonist
What does cortisol cause to happen in adipose tissue?
Lipolysis- breakdown of fat leading to thinning of the skin
Why do those with Cushing’s syndrome get depositions of fa around the face and central trunk?
Release of free fatty acids due to lipolysis increasing BG levels.
High levels of insulin as a result.
This causes he deposition of fat.
Which types of movement do those with Cushing’s struggle with?
Getting up from sitting
Reaching high up things
RECAP- list the symptoms of Cushing’s/
Moon face
Muscle atrophy
Muscle replaced w fat
Thin arms and legs
Easily bruised
Red striae
Oedema
Diabetes
Cardiac failure
Central obesity
Hypertension
Cushing’s syndrome can be described as being ACTH dependant or independent.
What causes ACTH dependant Cushing’s?
Pituitary tumour- this is known as Cushing’s disease
Ectopic ACTH secretion
Cushing’s syndrome can be described as being ACTH dependant or independent.
What causes ACTH independant Cushing’s?
Adrenal tumour
Which gland is producing the excess ACTH in Cushing’s disease?
Pituitary
RECAP- in normal people, when is the body’s level of cortisol the highest?
When we wake up, early in the morning
What system controls the release of aldesterone?
RAAS
Renin-angiotensin-aldosterone-system
Regarding the RAAS, what converts angiotensinogen into angiotensin 1?
Renin
Regarding the RAAS, what converts Angiotensin 1 into Angiotensin 2?
Angiotensin-converting enzyme
How does hyperaldosteronism increase blood presure?
Acts on distal renal tubules to increase sodium, also increasing absorption of water.
This increases blood volume which increases blood pressure
In screening for Conn’s disease or primary hyperaldosteronism, what does the ration of aldosterone:renin have to be greater than to indicate primary hyperaldosteronism?
Greater than 20x
What happens to potassium levels in hypertension?
They fall, potentially causing hypokalaemia.
->this is because sodium levels increase as sodium and water are absorbed so potassium is excreted
Which two hormone based conditions can cause hypertension relating to RAAS?
Cushing’s
Conn’s
What is Conn’s disease?
A hormonal condition in which one or both adrenal glands overproduce mineral corticoids from the zona glomerulosa
What is Pheochromocytoma?
A type of neuroendocrine tumour than grows from chromaffin cells.
Which symptom is present in majority with
Pheochromocytoma?
Hypertension
What are some other symptoms of a Pheochromocytoma?
Paroxysmal attacks
Headache
Sweating
Palpitations
Tremor
Pallor
Anxiety
What part of the adrenal gland is Pheochromocytoma associated with?
Adrenal medulla
What effect does a Pheochromocytoma have on blood glucose levels?
Hyperglycaemic effect
What do you do clinically if you have a suspicion than someone has Pheochromocytoma?
24hr urine collection to measure plasma metanephrines
What problems may arise when trying to remove a Pheochromocytoma?
When you touch the lesion, there is a high chance it releases a load of catecholamines into bloodstream.
This causes a rise in BP, causes tachycardia and potentially cardiac arrest
RECAP- which type of drug is used in tachycardia?
Beta blockers
Why does a deficit in hydroxylase cause adrenal hyperplasia?
-Lack of 21-hydroxylase to inhibit the synthesis of cortisol
-This removes the negative feedback on ACTH and CRH release
-Increased ACTH secretion responsible for the enlargement of adrenal glands
What is the cause of the vast majority of cases of congenital adrenal hyperplasia?
21-hydoxylase deficiency
In severe cases of congenital adrenal hyperplasia, what are some of the other issues?
Neonatal salt-losing crisis
Ambiguous genitalia in females*
*this is due to a shunt in which more testosterone is produced to make up for aldosterone
In incomplete defected cases of congenital adrenal hyperplasia, what are some of the other issues?
Pseudo-precocious puberty in boys
Hirsutism in women
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Which part of the adrenal gland produces too much catecholamines in Cushing’s?
Adrenal medulla
Which part of the adrenal gland produces too much corticoids in Conn’s?
Zona glomerulosa part of adrenal cortex
