Acromegaly (Growth Hormone Excess)

00:01 With growth hormone excess and acromegaly, take a look at your patient up above and to the right.

00:06 And we have frontal bossing.

00:09 If you take a look at the frontal area, you'll find that the bone is protruding forward.

00:13 And you can actually notice prognatism in this patient as well.

00:16 Look at the jaw, extremely well demarcated.

00:19 You take a look at the patient down below and you find exaggerated prognatism.

00:25 in a patient that has acromegaly.

00:28 Excessive sweating with all this growth hormone in an adult, you can then expect there to be hyperglycemia.

00:35 There might be carpal tunnel syndrome because of excess, as you said, soft tissue issues.

00:40 Growth, growth growth, high incidence of colon polyps; correlate with skin tags on exam, and that's something that you want to pay attention to, from a clinical point of view.

00:51 Remember, acromegaly, you're thinking about the internal organs that are growing, including bones, and viscera.

00:57 Maybe the tongue, may be the frontal bone, maybe the jaw, and hyperglycemia.

01:03 Cardiovascularly.

01:05 This is a patient that may then die from it.

01:10 Growth Hormone from head to toe.

01:11 Enlarged head, enlarged sella, large and wide spaced teeth, protruding chin, prognathism, deep voice, blood pressure elevated, osteoarthritis, big feet, everything's increased.

01:26 Whenever you suspect acromegaly in an adult, usually for you, it'll be the presence of a adenoma within the anterior pituitary.

01:35 Invasion into the left cavernous sinus with encasement of the internal carotid artery is something that you would perhaps find in MRI that we're seeing here in this picture.

01:48 Superior bowing of the optic chiasm, resulting in and I'll show you 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 the pituitary adenoma is not able to see those areas.

02:11 The pressure on the optic chiasm produces this particular picture or lack thereof.

02:19 Diagnosis of acromegaly.

02:20 I want you to focus upon the graph here and take a look at the x and y axis.

02:26 on the x axis would be the time in minutes after oral glucose.

02:32 And what kind of effect an influence it should normally have? On growth hormone, which is the y axis.

02:40 Before we dive into the pathology, let us first predict as to what you can expect normally.

02:45 So that when you take a look at the path, you'll be able to easily identify your patient.

02:52 Okay, so you've taken oral glucose.

02:55 The usual dosage that we use in medicine is about 75 grams and bolus.

03:00 That's a pretty big bolus, orally of glucose that you're taking.

03:06 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.

03:30 So therefore, after taking glucose, it should normally, take a look at the green line over a certain period of time, you find a drop in your growth hormone.

03:44 So, when you compare this to acromegaly, you'll notice that after consumption of glucose, that over a period of time, the growth hormone seems to have its own mind.

03:56 Autonomously increasing.

03:59 Diagnosis of acromegaly Screening.

04:02 Remember, it is not growth hormone that you're going to be looking for.

04:07 It's IGF-1.

04:08 Why? Give me two reasons that we've talked about over and over again.

04:13 At least give me one.

04:15 One, will be one in which the half-life of growth hormone is shorter than IGF-1.

04:21 And secondly, remember that the growth hormone has been released at night overrides any negative feedback that IGF-1 has on somatostatin.

04:34 Thus, IGF-1 becomes the much preferred screening indicator.

04:42 Confirmation: Non-suppression of growth hormone after 30 minutes and 60 minutes of consuming oGTT stands for Oral Glucose Tolerance Test.

05:00 We'll be using this acronym a lot when we get into diabetes mellitus.

05:07 But after administering glucose, you'll notice the red line when growth hormone did not get suppressed.

05:14 Welcome to Confirmation.

05:17 What's your next step of management? Remember? Previously, I just, just told you that acromegaly usually represents an adenoma in the pituitary.

05:28 Thus, if you do an MRI of the head, you should be able to find a tumor.

05:36 What your goal? It's to normalize the growth hormone IGF level.

05:40 Treatment of choice.

05:41 Treatment of choice.

05:43 transphenoidal surgery, (cure in 50% less likely with macroadenoma) because of the size and the residual tissue that may actually exist.

05:54 Somatostatin analog.

05:56 Octreotide, is adjunct to the medical treatment.

05:59 So here interesting enough, it is your transphenoidal surgery, which would be the treatment of choice because of the size of the adenoma usually for growth hormone and that's an issue.

06:11 Whereas, if it's a microadenoma, usually it'd be a prolactin that's being released.

06:16 Macroadenoma, more along the lines of your growth hormone.

06:19 And remember, the number one question that you asked yourself anytime that there is an adenoma, is functioning or nonfunctioning.

06:28 This obviously it's functioning.

06:32 Acromegaly. What else? Also inhibits glucagon, insulin, and gastrin.

06:36 Long acting synthetic analogue of somatostatin, used to treat acromegaly, carcinoid, gastrinoma.

06:43 This is a nice little list of octreotide and all the different indications in which you may want to use it.

06:52 Acromegaly. It inhibits serotonin and carcinoid.

06:57 It inhibits gastrin and gastrinoma.

07:01 It inhibits glucagon and glucagonoma and other endocrine tumors.

07:06 So, from physio and into pathology and forevermore, think of somatostatin as being the hormone that inhibits all others.

07:19 From the head with GH, and all the way down through your GI referring to carcinoid and also your gastronoma.

07:29 The side effects.

07:30 Gallstone formation and some cardiac conduction abnormalities is something that you're worried about as a result of acromegaly and treatment.

07:44 30% my response to cabergoline.

07:47 That was interesting.

07:49 Remember, whenever growth hormone is being released, there's every possibility that prolactin might as well.

07:55 And yes, some of these patients, they'll actually respond to dopamine.

08:02 We have a drug, a growth hormone receptor antagonist, and it's called pegvisomant.

08:09 At the growth hormone receptor antagonist, And what does it do? It inhibits and reduces IGF-1 and 90% of your patients.

08:19 Radiation only as adjunctive here.

08:23 Post surgically once again to deal with perhaps the residual tissue.