Endocrine

Question 1

How is Grave’s diagnosed? What would you expect to be the TSH and T3 / T4 levels?

Answer 1

TSH antibodies (activate the TSH receptor)

TSH very low (inhibited by high T3 and T4 levels)
T3 / T4 high

Question 2

What test is used to diagnose Cushing’s disease?

Answer 2

Dexamethasone suppression test

tests for adrenal hyperactivity

Question 3

Why is phosphate low in primary hyperparathyroidism but high in tertiary hyperparathyroidism? What is the difference between 1/2/3 forms?

Answer 3

Primary: Parathyroid overactive e.g. due to tumour
Secondary: Parathyroid overactive due to low Vit D or calcium levels.
Tertiary: Long term secondary results in hyperplasia of parathyroid glands.

PTH causes increased calcium/Phos absorption in intestines, increased resporption from bone and increased reabsorption of calcium but excretion of phosphate in the kidneys.

In primary, the PTH is moderately raised, so more Phosphate is excreted than absorbed/resorbed.
In tertiary, PTH is so high, that too much phosphate is absorbed/resorbed to be excreted.

Question 4

Where is calcidiol converted into the active form of Vit D?

Answer 4

7-dehydrocholesterol –> cholecalciferol (D3) [Skin]

• -> Calcidiol (25(OH) [Liver]
• -> Calcitriol (1,25(OH2) [Kidney] “Active form”

Question 5

What are the abnormal levels for blood sugar for fasting and random blood glucose?

Answer 5

Normal Fasting: 5.6 - 7.0

Normal Random: 7.8 - 11.0

Question 6

True or false, type 2 diabetes has a stronger genetic component than Type 1?

Answer 6

True

Question 7

Give two symptoms of diabetes

Answer 7

Polyuria
Polydipsia
Weight loss
Fatigue
Blurred vision

Question 8

What is the pathophysiology of diabetes insipidus?

What is the difference between cranial and nephrogenic DI?

Answer 8

Cranial DI: Reduced ADH production resulting in excessive urination (>3L/day)

Nephrogenic DI: Reduced renal sensitivity to ADH resulting in excessive urination (>3L/day)

Question 9

Give two complications of diabetes?

Answer 9

Nephropathy
Neuropathy
Retinopathy
CVD

Question 10

How is diabetes insipidus treated?

Answer 10

Desmopressin (ADH analogue)

Treat cause e.g. pituitary tumour

Question 11

How is diabetes insipidus diagnosed?

Answer 11

Water deprivation test + measure urine output
+ Desmopressin to see if cranial/nephrogenic.

[Monitor U&E + serum/urine osmolality]

Question 12

Which is more common cranial or nephrogenic diabetes insipidus?

Answer 12

Cranial (ADH production is reduced)

[vs. nephrogenic where there is renal insensitivity to ADH]

Question 13

What is cushing’s disease?

Answer 13

Raised glucocorticoids (cortisol) driven by increased adrenocorticotropic hormone production (ACTH)

Question 14

Give two signs of cushing’s disease

Answer 14

Buffalo hump
Moon face
Weight gain
Mood changes
Hypertension
Raised plasma cortisol

Question 15

What is addison’s disease?

Answer 15

Adrenal insufficiency (hypoadrenalism)

• Low cortisol
• Low aldosterone

Primary = adrenal gland failure
Secondary = low ACTH or CRH

Question 16

Does Addison’s disease cause hypo or hyperkalaemia?

Answer 16

Addison’s produces hyperkalaemia and hyponatraemia.

This is due to low aldosterone levels.

Question 17

True or false, ACEi are known to produce hyperkalaemia?

Answer 17

True. By inhibiting aldosterone production, more sodium is wasted in urine and more potassium is absorbed.

Question 18

What is thyrotoxicosis and myxoedema?

Answer 18

Thyrotoxicosis = Hypothyroidism 
Myxoedema = Hyperthyroidism

Question 19

Give three signs/symptoms of hyperthyroidism?

Answer 19

Weight loss
Heat intolerance
Palpitations
irritability 
Hair thinning
Goitre
Tachycardia

Question 20

True or false, hyperthyroidism is more common in women?

Answer 20

True. 5x more common.

Question 21

What is the most common form of hyperthyroidism?

Answer 21

Grave’s disease (60-80% of cases)

Question 22

Give three signs/symptoms of hypothyroidism

Answer 22

Fatigue
Cold intolerance
Weight gain
Constipation
Bradycardia
Dry hair 
Cold hands
Puffy face

Question 23

What medical treatment is given to patients with hyperthyroidism?

Answer 23

Carbimzole
Proplythiouracil
Beta blocker

Question 24

What causes SIADH? What lab inverstigations would confirm SIADH?

Answer 24

Excessive ADH production causes blood volume increase and raised BP, which in turn switches off the RAS system, decreases Aldosterone so sodium gets wasted into the urine.

Low plasma osmolality
High urine osmolality

Question 25

What causes acromegaly?

Answer 25

Hypersecretion of growth hormone by pituitary gland

Question 26

Give two signs of acromegaly

Answer 26

Acral enlargement (large periperhies)
Hyperhidrosis
Arthralgia
Headaches
Macroglossia

Question 27

What is the diagnostic test for acromegaly?

Answer 27

Glucose tolerance test

Glucose inhibits growth hormone

Question 28

What is the treatment for acromegaly?

Answer 28

Transsphenoidal pituitary surgery
Somatostatin analogues (inhibit Growth hormone)

Question 29

Give two common complications associated with acromegaly

Answer 29

Diabetes
CVD
Osteoporosis
Heart failure

Question 30

What is Conn’s syndrome?

Answer 30

Hyperaldosteronism (Mostly due to adenoma)

Results in increased plasma Na + Hypokalaemia + water retention (increased BP)

Question 31

Give two signs of hypercalcaemia

Answer 31

Bones - Bone pain
Stones - Kidney stones
Groans - Abdominal pain, N&V, constipation.
Moans - Depression, Psychosis.

Question 32

In hyperkalaemia, what medication is given as the 1st line to reduce the risk to the heart?

Answer 32

Calcium gluconate

Cardio protective