Acromegaly and Giantism

Question 1

What is the difference between Acromegaly and Giantism?

Answer 1

They are both caused by excess growth hormone. Giantism occurs in people (children) whos growth plates have not yet fused when the excess GH secretion occurs. They will increase in height very quickly.

Acromegaly occurs in people who’s growth plates have already fused (adults), due to the fused growth plates the y don’t increase in height but their hands and feet will increase in many sizes over a short period of time and their face will change shape and increase in size.

Question 2

What are the symptoms of acromegaly?

Answer 2

Increase over short period of time in shoe size (5 or 6 sizes). Enlarged hands (e.g. ring or gloves no longer fit)
Thick lips + tongue
Coarse facial features
Headaches and sweating
Vision problems (bitemporal hemianopia)
Diabetes
Hypertension
Sleep apnoea

Question 3

What are the possible treatments for acromegaly?

Answer 3

Surgical removal of tumour (transsphenoidal surgery)

Radiotherapy

Question 4

What usually causes acromegaly/giantism?

Answer 4

Pituitary tumour

Question 5

If there is hypersecretion of GH, how is this treated?

Answer 5

Somatosatin analogues
GH receptor antagonist
These are both expensive and have to be taken for the rest of the patients life.

Question 6

What are some of the benefits and negatives to somatosatin analogues?

Answer 6

Benefits:
Improves sweating, headahces, sleep apnoea and soft tissue overgrowth.
Shrinks tumour. Normalises GH and IGF-1 levels

Question 7

How does an oral glucose tolerance test work?

Answer 7

Glucose increases growth hormone inhibiting hormone (somatostatin release), so decrease GH levels.

Glucose is given orally and normally this would cause a decrease in GH levels but if they have a tumour secreting excess the level won’t be suppressed.

Question 8

What affect does GH have on blood glucose?

Answer 8

It is hypoglycaemic so causes a decrease in blood glucose levels.