Endocrinology

Question 1

At what times of day are the levels of cortisol highest and lowest in the body?

Answer 1

Highest= 8/9am
Lowest= midnight

Question 2

Which molecule is most of the cortisol in the blood bound to?

Answer 2

Cortisol binding globulin

Question 3

What does renin do?

Answer 3

Catalyses the conversion of angiotensinogen to angiotensin I

Question 4

What does angiotensin 2 do?

Answer 4

Stimulates aldosterone release by binding to angiotensin receptors

Question 5

What does aldosterone do?

Answer 5

Acts at renal distal convoluted tubule to cause sodium retention and potassium loss

Question 6

What are some biochemical features of Addison’s disease?

Answer 6

Hyponatraemia, hyperkalaemia, hypoglycaemic and mild anaemic

Question 7

What are diagnostic tests for Addison’s disease?

Answer 7

Low 9am cortisol with raised ACTH, Syncathen test

Question 8

What is Addison’s disease?

Answer 8

Primary adrenal insufficiency from destruction of the adrenal gland affecting all zones

Question 9

What thyroid antibodies are associated most with 1) hashimotos 2) Grave’s

Answer 9

1) anti-TPO
2) TSH receptor

2) Anti-TSH (and anti-TPO)

Question 10

How can iron and calcium supplements affect levothyroxine treatment?

Answer 10

Both can reduce absorption of levothyroxine so should be taken 4 hours apart

Question 11

What is first line test in diagnosing acromegaly?

Answer 11

Serum IGF-1

Question 12

What medical treatment can be used in acromegaly?

Answer 12

Somatostatin analogues, GH receptor blockers

Question 13

What are some complications of acromegaly?

Answer 13

Diabetes, hypertension, cardiomyopathy/arrhythmias, colorectal carcinoma, arthropathy, hypogonadism