Endocrinology

Question 1

What is the action of insulin on glucose?

Answer 1

It causes increased glucose uptake by liver and muscle tissue to be converted and stored as glycogen
It causes increased use of glucose by cells

Question 2

What are the effects of glucagon on the body?

Answer 2

This is a catabolic hormone
It promotes breakdown of glycogen in the liver to glucose
It also promotes glucose production in the liver (Gluconeogenesis)

Question 3

What is ketogenesis?

Answer 3

When there is not enough glucose the liver breaks down fatty acids to water soluable ketones, which can be used as fuel

Question 4

What are the triad of symptoms for hyperglycaemia?

Answer 4

Polydipsia due to dehydration
Polyuria due to high urine glucose drawing water into the urine
Weight loss (mostly due to dehydration)

Question 5

What investigations should be done for a first presentaiton of diabetes?

Answer 5

Baseline bloods including FBC, renal profile (U&E) and a formal laboratory glucose
Blood cultures should be performed in patients with suspected infection (i.e. with fever)
HbA1c can be used to get a picture of the blood sugar over the previous 3 months. This gives an idea of how long they have been diabetic prior to presenting.
Thyroid function tests and thyroid peroxidase antibodies (TPO) to test for associated autoimmune thyroid disease
Tissue transglutaminase (anti-TTG) antibodies for associated coeliac disease

Question 6

What is the management of hypoglycaemia?

Answer 6

If the patient is conscious then give rapid acting glucose such as orange juice and a slower acting glucose such as biscuits
If the patient is unconscious then they require IV glucose and IM glucagon
If they have a cannula then give 10% IV dextrose in 200ml saline in an hour

Question 7

How much does 1 unit of insulin roughly reduce blood glucose by?

Answer 7

4mmol/L

Question 8

What is the most common form of adrenal insufficiency?

Answer 8

Autoimmune primary insufficiency

Question 9

What is secondary adrenal insufficiency?

Answer 9

This is where there is not enough ACTH being produced by the pituitary, this results in less cortisol being produced
This can be due to congenital underdevelopent of the pituitary, surgery, infection or loss of blood flow

Question 10

What is tertiary adrenal insufficiency?

Answer 10

This is when the hypothalamus does not produce enough CRH to stimulate enough ACTH production by the pituitary
This is usually the result of long term steroid use (more than 3 weeks), this is why steroids must be tapered to reduce the chances of this happening

Question 11

What are the features of adrenal insufficiency?

Answer 11

Lethargy
Nausea and vomiting
Reduced appetite
Abdo pain
Muscle weakness and cramps
Bronzing of the skin in addisons (primary) due to high ACTH levels

Question 12

What investigations should be done for children with suspected adrenal insufficiency?

Answer 12

U and Es for hyponatraemia and hyperkalaemia
Blood glucose for hypoglycaemia
Cortisol, aldosterone, ACTH and renin levels
Short synthacten test - this is synthetic ACTH and should cause a rise in cortisol from healthy adrenals, performed in morning, a rise less than double baseline demonstrates primary adrenal insufficiency (addisons)

Question 13

How is adrenal insufficiency treated?

Answer 13

IT is treated with hydrocortisone to replace corisol and fludrocortisone to replace aldosterone if this needs replacing
They are given a steroid card and need to have steroids increased if they are unwell

Question 14

What are the sick day rules for patients with adrenal insufficiency?

Answer 14

They require a plan to increase their steroids
They need their blood glucose monitored regularly
If there is D and V then they may require IV steroids

Question 15

How do patients present in addisonian crisis?

Answer 15

Reduced consiousness
Hypotension
Hypoglycaemia, hyponatraemia, hyperkalaemia

Question 16

What is the management of addisonian crisis?

Answer 16

They require urgent hydrocortisone before performing investigations
Intensive monitoring
IV resuscitation
Correct hypoglycaemia
Careful monitoring of fluids and electrolytes

Question 17

What enzyme is deficient in congenital adrenal hyperplasia and what is the result of this?

Answer 17

There is a congenital deficiency of the 21 hydroxylase enzyme
This results in an underproduction of cortisol and aldosterone
There is an overproduction of androgens

Question 18

What is the inheritance pattern of congenital adrenal hyperplasia?

Answer 18

It is inherited in an autosomal recessive pattern

Question 19

What is the pathophysiology behind congenital adrenal hyperplasia?

Answer 19

There is a deficiency of 21-hydroxylase that converts progesterone to cortisol and aldosterone
21-hydroxylase is not required to synthesise testosterone so all of the progesterone is converted down this pathway causing excessively high testosterone

Question 20

How do severe cases of congenital adrenal hyperplasia present?

Answer 20

In females they present with virilised genetalia due to the high levels of testosterone
This causes an enlarged clitoris
They have hyponatraemia, hyperkalaemia and hypoglycaemia that presents shortly after birth with poor feeding, vomiting, dehydration and arrhythmias

Question 21

What is the presentation of mild congenital adrenal hyperplasia when the children get older?

Answer 21

Female patients:
Tall for age
Facial hair
Absent periods
Deep voice
Early puberty

Male patients:
Tall for age
large penis
Small testicles
early puberty

Question 22

What is the management of congenital adrenal hyperplasia?

Answer 22

Cortisol replacement, usually with hydrocortisone, similar to treatment for adrenal insufficiency
Aldosterone replacement, usually with fludrocortisone
Female patients with “virilised” genitals may require corrective surgery

Question 23

What is the effect of growth hormone in children?

Answer 23

It causes release of insulin like growth factor 1 from the liver that promotes growth

Question 24

What are the causes of growth hormone deficiency?

Answer 24

Congenital growth hormone deficiency:
-genetic mutations to GH or empty sella syndrome where the pituitary does not form properly
Aquired growth hormone deficiency:
-Surgery
-Infection
-trauma
Can also occur in conjunction with other deficiencies such as in hypopituitism

Question 25

How does growth hormone deficiency present?

Answer 25

In neonates:
-Micropenis
-Severe jaundice
-Hypoglycaemia
Older infants:
-Poor growth
-Short stature
-Slow development of movement and strength

Question 26

What are the investigations for growth hormone deficiency?

Answer 26

A stimulation test using medications such as glucagon that stimulate growth hormone release
Also look at other hormones such as thyroid and adrenals
MRI for pituitary abnormalities
X ray to determine bone age
Genetic testing for Turners and prader willi

Question 27

What is the management of growth hormone deficiency?

Answer 27

Daily subcutaneous injections of growth hormone (somatropin)
Treatment of other associated hormone deficiencies
Close monitoring of height and development

Question 28

What are the causes of congenital hypothyroidism?

Answer 28

Either an underdeveloped thyroid gland called dysgenesis

Or a fully developed gland that doesn’t produce enough hormone called dyshormonogenesis

Question 29

How is congenital hypothyroidism usually picked up?

Answer 29

On the newborn blood spot test
Can also present with prolonged jaundice
Poor feeding
Constipation
Increased sleeping
Reduced activity

Question 30

What is the most common form of aquired hypothyroidism?

Answer 30

autoimmune hypothyroidism e.g. hashimotos thyroidistis

It is associated with anti thyroid peroxidase (Anti-TPO) antibodies and antithyroglobulin antibodies

Question 31

What can undiagnosed hypothyroidism cause in children?

Answer 31

It causes severe neurodevelopmental and interlectual disability