With growth hormone excess and acromegaly,
take a look at your patient up above and to
the right and we have frontal bossing.
If you take a look at the frontal area, you’ll
find that the bone is protruding forward and
you can actually notice prognathism in this
patient as well.
Look at the jaw, extremely well demarcated.
You take a look at the patient down below
and you find exaggerated prognathism in the
patient that has acromegaly.
Excessive sweating; with all these growth
hormone in an adult, you can then expect there
to be hyperglycemia; there might be Carpal
tunnel syndrome because of excess, as we’ve
said, soft tissue issues… growth, growth,
growth; high incidence of colon polyps co-relate
with skin tags on exam and that’s something
that you want to pay attention to from a clinical
point of view.
Remember, acromegaly, you’re thinking about
the internal organs that are growing including
bones, the viscera, maybe the tongue, maybe
the frontal bone, maybe the jaw and hyperglycemia.
Cardiovascularly, this is a patient that may
then die from it.
Acromegaly, what we’re seeing here is the
We have two leads of an ECG in which you are
then going to identify your patient with heart
Watch this, here’s V1, how in the world…
you’re thinking to yourself, “You’re
really going to tie in electrocardiogram with
what’s going on here with acromegaly, Dr.
I have to.
What do we say would be perhaps a common cause
of death in acromegaly?
So, this is not a joke.
Tell me the size of your heart perhaps in
a patient with acromegaly.
Good, it is going to be enlarged.
So, how would you go about identifying this?
Take a look at V1, V1 in this patient.
V1 is a precordial lead that is located medially,
is it not?
Whereas V5 is a precordial lead that is then
located in your lateral section.
And so, therefore, what you can expect here
in acromegaly will be your left axis deviation.
Next, what we have is our blood glucose.
Normally, your glucose should be approximately
Now, technically speaking, instead of getting
above 126 with fasting then you’re thinking
about your hyperglycemia and perhaps diabetes,
but then here, you have a normal patient with
that bar that you are seeing here on this
graph, orange, whereas you have a patient
With all that growth hormone, there is going
to be quite a bit of insulin resistance resulting
in hyperglycemia and here is an example, is
a blood glucose of what?
Growth hormone from head to toe… enlarged
head, enlarged sella, large and widely spaced
teeth, protruding chin… prognathism; deep
voice, blood pressure elevated, osteoarthritis,
big feet… everything’s increased.
Whenever we suspect acromegaly in an adult,
usually for you, it will be the presence of
a adenoma within the anterior pituitary.
Invasion into the left cavernous sinus with
encasement of the internal carotid artery
is something that you would perhaps find in
the MRI that we’re seeing here in this picture.
Superior bowing of the optic chiasm resulting
in and I’ll show a cartoon down below which
is then showing you bitemporal hemianopsia.
OD is the right eye, OS is the left eye and
that, that you see as being squiggly lines
on the temporal regions would be those areas
in which the patient with a pituitary adenoma
is not able to see those areas.
The pressure on the optic chiasm produces
this particular picture or lack thereof.
Diagnosis of acromegaly...
I want you to focus upon the graph here and
take a look at the X and Y axis.
On the X axis would be the time in minutes
after oral glucose and what kind of effect
and influence it should normally have on growth
hormone which is the Y axis.
Before we dive into the pathology, let us
first predict as to what you can expect normally
so that when you take a look at the path,
you’ll be able to easily identify your patient.
Okay, so, you have taken oral glucose, the
usual dosage that we use in medicine is about
75 grams of bolus.
That’s a pretty big bolus orally of glucose
that you’re taking.
What should happen normally in terms of being
able to properly metabolize that glucose is
to make sure that you inhibit as much as you
can of the stress hormones and bring in your
major anabolic insulin, right?
So, what happens in acromegaly?
Remember that growth hormone is a stress hormone.
So, therefore, after taking glucose, it should
normally… take a look at the green line…
over certain period of time, you find a drop
in your growth hormone.
So, when you compare this to acromegaly, you’ll
notice that after consumption of glucose that
over period of time, huh, the growth hormone
seems to have its own mind, autonomously increasing.
Diagnosis of acromegaly… screening.
Remember, it is not growth hormone that you
are going to be looking for, it’s IGF1.
Give me two reasons that we’ve talked about
over and over again.
At least give me one, haha!
One would be one in which the half-life of
growth hormone is shorter than IGF1 and secondly,
remember that the growth hormone that’s
being released at night overrides any negative
feedback that IGF1 has on somatostatin.
Thus, IGF1 becomes the much preferred screening
Confirmation… non suppression of growth
hormone after 30 minutes and 60 minutes of
consuming OGTT, stands for Oral Glucose Tolerance
We’ll be using this acronym a lot when we
get into diabetes mellitus.
But, after administering glucose, you’ll
notice the red line with growth hormone did
not get suppressed… welcome to confirmation.
What’s your next step of management?
Remember, previously I just, just told you
that acromegaly usually represents an adenoma
in the pituitary.
Thus, if you do an MRI of the head, you should
be able to find a tumour.
What’s your goal?
It’s to normalize your growth hormone IGF
Treatment of choice… treatment of choice
transphenoidal surgery, cure 50 percent less
likely with macroadenoma because of the size
in the residual tissue that may actually exist.
Somatostatin analogue… octreotide… is
adjunct to the medical treatment.
So, here, interesting enough, it is your transphenoidal
surgery which would be the treatment of choice
because of the size of the adenoma usually
with growth hormone and that’s an issue.
Whereas if it’s a microadenoma, usually
it would be prolactin that’s being released;
macroadenoma more along the lines of your
growth hormone and remember, the number one
question that you ask yourself any time that
there is an adenoma, “Is this functioning
This obviously is functioning.
Acromegaly… what else?
Also inhibits glucagon, insulin and gastrin;
long acting synthetic analogue of somatostatin
used to treat acromegaly, carcinoid, gastrinoma…
this is a nice little list of octreotide and
all the different indications in which you
may want to use it.
Acromegaly, it inhibits serotonin and carcinoid;
it inhibits gastrin and gastrinoma; it inhibits
the glucagon and glucagonoma and other endocrine
So, from physio and endopathology and forevermore,
think of somatostatin as being the hormone
that inhibits all others from the head with
GH and all the way down through your GI referring
to carcinoid and also your gastrinoma.
The side effects… gall stone formation and
some cardiac conduction abnormalities is something
that you’re worried about as a result of
acromegaly and treatment.
30 percent may response to cabergoline.
That was interesting.
Remember, whenever growth hormone is being
released, there’s every possibility prolactin
might as well and yes, some of these patients
that will actually respond to dopamine.
We have a drug, a growth hormone receptor
antagonist and it is called pegvisomant.
That’s a growth hormone receptor antagonist.
And what does it do?
It inhibits and reduces IGF1 in 90 percent
of your patients.
Radiation, only as adjunctive here, post-surgically
once again to deal with perhaps the residual