acromegaly
why might people with acromegaly have vision disorders headaches
growing pituitry disorder courses nerve entrapment
Acromegaly is caused by excess circulating levels of
growth hormone (GH) and insulin-like growth factor 1 (IGF1) which typically result from a GH-secreting pituitary adenoma
Acromegaly happens because your pituitary gland produces to much
growth hormone This is usually caused by a non-cancerous tumour in the pituitary gland called an adenoma
pegvisomant
growth hormone receptor antagonist daily injection by patient Unlike dopamine agonists and somatostatin analogs, pegvisomant does not stop the production of GH by the tumor. Instead it stops the hormone from taking effect in the body
people with acromegLY HAVE
high blood pressure
Three different types of medicine are used
monthly injection of either octreotide, lanreotide or pasireotide daily pegvisomant injection Bromocriptine or cabergoline tablets
acromegaly causes
muscle weekness enlargement of hands and feet thickning of soft tissue courseing corse facial features enlarged tonge nose protruding jaw increased sweeting enlargment of organs liver spleen and heart
Most people with acromegaly will have a pituitary tumour that needs to be
surgically removed
If you do not get treatment, you may be at risk of developing
type 2 diabetes high blood pressure hypertension heart disease disease of the heart muscle cardiomyopathy arthritis bowel polyps, which can potentially turn into bowel cancer if left untreated
After treatment
you'll need regular follow-up appointments with your specialist for the rest of your life. These will be used to monitor how well your pituitary gland is working, check you're on the correct hormone replacement treatment and make sure the condition does not return.
Early symptoms include:
swollen hands and feet - you may notice a change in your ring or shoe size tiredness and difficulty sleeping, and sometimes sleep apnoea gradual changes in your facial features, such as your brow, lower jaw and nose getting larger, or your teeth becoming more widely spaced numbness and weakness in your hands, caused by a compressed nerve carpal tunnel syndrome
can't simply test for the level of growth hormone (GH) in your body because
the level varies so much in one day—even in someone without acromegaly
Bromocriptine or cabergoline tablets
these can stop growth hormone being produced, but they only work in a small proportion of people.
Dopamine agonists are often thought of as first line medical therapy however
they are less effective than the other medications. easier to take and are less costly If dopamine agonists are not working change your medication to 'somatostatin analogs
daily pegvisomant injection
this blocks the effects of growth hormone and can significantly improve symptoms
injection of either octreotide, lanreotide or pasireotide
this slows down the release of growth hormone and can sometimes also shrink tumours
acromegaly usully affects adults aged
30 to 50
Long-term biochemical control is achieved in fewer than
65% of patients following surgical resection
case study
A 55 year old man went to see his GP complaining of headaches, and indicated that he had increased shoe size. Upon examination he had coarse facial features. The GP took some blood for random (non-fasting) analysis. The results are shown below: Glucose 15 mmol/L (2.7- 7.9 mmol/L) Random GH 5 mU/L (<10) Discuss the results and the testing strategy. Upon receiving the results the GP arranged an oral glucose tolerance test, with measurement of glucose and growth hormone. Glucose levels showed mild glucose intolerance Oral glucose tolerance test Time (Mins) GH (mU/L) 0 (fasting) 6 30 7 60 10 90 8 120 8 Comment on the results above and differential diagnosis? Suggest additional investigations? growth hormone has gone up glucose should inhibit growth hormone and it should go down What are the treatment options?
tumours in other prts of body
More often, the tumor produces growth hormone-releasing hormone (GHRH), the hormone that tells the pituitary gland to make more GH
excessive growth hormone cause in children and adults
gigantism children acromegaly adults
Bone Complications from Acromegaly
Excess growth hormone (GH) secreted by a tumor (usually a pituitary tumor) can cause your bones to grow too much. Bone overgrowth is especially noticeable in the face, and it can cause problems for your teeth if your jaw grows too much Bone health can also be affected by acromegaly. Too much GH can change the way your body uses vitamin D, a vitamin that's absolutely essential for bone health. Without it, your body can't use calcium well, so your bones don't get the calcium they need. This may lead to osteoporosis—low bone density—and that puts you at a higher risk of a fracture Hypercalcemia (too much calcium in the blood) and hypercalciuria (too much calcium in the urine) are possible complications of acromegaly; both of them mean that your body isn't using calcium. However, with treatment, your body should again be able to properly use vitamin D and calcium to build strong, healthy bones
Treatment of patients with acromegaly is aimed at normalizing
GH and/or IGF1 levels to ameliorate signs and symptoms of the disease
Oral Glucose Tolerance Test (OGTT)
Growth hormone levels and blood glucose levels are also connected. In someone without acromegaly, a higher blood glucose level usually causes the body to stop producing GH. Therefore, a doctor will purposely raise your blood glucose level using an OGTT and watch how your GH level responds. To begin the test, your doctor will measure your blood glucose level and your GH level. You'll then drink 75 g of a very sugary drink—a glucose drink. Over the course of the next 2 hours, the doctor will test your glucose and GH levels 4 more times: 30, 60, 90, and 120 minutes after you've had the glucose drink. If your GH level doesn't drop to below 1 ng/mL (ng/mL is the standard measurement used for GH levels) during the OGTT, you have acromegaly. Your GH level should respond to so much glucose by dropping, so if it doesn't, that tells the doctor that your body isn't listening to its own signals: The delicate feedback loop of the endocrine system has been disturbed. (To learn more about the endocrine system feedback loop and how it regulates itself, you can read our endocrine system
Imaging Tests to Confirm Acromegaly
Since 95% of acromegaly cases are caused by a pituitary tumor, the doctor will most likely have a magnetic resonance imaging (MRI) scan done of your pituitary gland. The MRI should show the doctor exactly where the tumor is and how big it is. If you have an MRI done and the doctor can't see a pituitary tumor, then you may be one of those rare cases of acromegaly caused by a non-pituitary tumor. In that case, the doctor may order a computerized tomography (CT) scan of possible tumor sites (abdomen and chest are common sites). Additionally, the doctor may test your growth hormone-releasing hormone (GHRH) levels since often, non-pituitary tumors causing acromegaly make GHRH (which then causes your pituitary gland to over-produce GH).
Because of the risk of bowel polyps what screening might be recomended
a colonoscopy
Diagnosing acromegaly involves 2 key blood tests
a test to check the level of the insulin-like growth factor-1 (IGF-1) and an oral glucose tolerance test (OGTT)
In rare cases, acromegaly is caused by
a tumour in another part of the body, such as the lungs, pancreas or another part of the brain. It may also be linked to some genetic conditions.
As time goes on, common symptoms include
abnormally large hands and feet large, prominent facial features such as the nose and lips and an enlarged tongue skin changes - such as thick, coarse, oily skin; skin tags; or sweating too much deepening of the voice, as a result of enlarged sinuses and vocal cords joint pain tiredness and weakness headaches blurred or reduced vision loss of sex drive abnormal periods in women and erection problems in men
Brain scans
f your blood tests show a high level of growth hormone and IGF-1, you might have an MRI scan of your brain. This will show where the adenoma is in your pituitary gland and how big it is. If you can't have an MRI scan, a CT scan can be carried out, but this is less accurate
Dopamine agonists
bromocriptine cabergoline inhibit GH release from the tumor. They work by stimulating natural receptorsof the hormone dopamine on the surface of the tumor. This sends messages into the tumor cells to stop producing GH
an individiual with advanced acromegaly is at risk of serious complications such as
coronary heart disease cerobvascular disease diabetes mellitus
Testing Insulin-like Growth Factor-1 (IGF-1)
nsulin-like growth factor-1 (IGF-1) is a hormone that's closely tied to growth hormone. GH tells the body to make IGF-1, which in turn causes tissues in your body to grow. In someone without acromegaly, a high IGF-1 level is the body's signal to stop producing GH. For a person with acromegaly, though, the body continues producing GH, regardless of high IGF-1 levels. IGF-1 levels are much more constant throughout the day than GH levels, so doctors measure IGF-1 levels using a blood test. An elevated IGF-1 level may indicate acromegaly
somatostatin analogs
octreotide injected monthly lanreotide injected montly somatostatin analogs decrease the size of the tumor in most patients
Removing the tumour should instantly lower your levels
of growth hormone and relieve pressure on the surrounding tissue. Often, facial features start to return to normal and swelling improves within a few days.
oral glucose tolerance test carol
performed to confirm a diagnosis of diabetes mellitus and to aid in diagnosing hypoglycemia as well as acromegaly fast for 8 to 14 hours water allowed 75g glucose consume within 5 mins blood sample at 0 and then every 30 minds till 150 mins or 2 hours measure growth hormone levels in normal adults will surpress growth hormone at less then 2 mU/L failure to supress sugess acromegaly failure to supress at 5mU/l risk of diabeters heart disease hypertension monitor
Diagnosing acromegaly
photographs of yourself that span the past few years to look for the tell-tale gradual changes glucose tolerance test For people without acromegaly, drinking the solution should stop growth hormone being released. In people with acromegaly, the level of growth hormone in the blood will remain high measure the level of another hormone, called insulin-like growth factor 1 (IGF-1). A higher level of IGF-1 is a very accurate indication that you might have acromegaly
If surgery isn't possible, not all of the tumour could be removed or medication hasn't worked, then you may be offered
radiotherapy This can eventually reduce your growth hormone levels, but it may not have a noticeable effect for several years and you may need to take medication in the meantime
consontrtions og IGF-1 are
raised in people with acromegaly
The type of treatment offered for acromegaly depends on the symptoms you have. Usually the goal is to
reduce growth hormone production to normal levels relieve the pressure a tumour may be putting on surrounding tissues treat any hormone deficiencies improve your symptoms