Know the important concerns in Acromegaly

Acromegaly:

Is the excess of Growth hormone in an adult. When this occurs in a child, it leads to gigantism.

Etiology - Pituitary tumor,  GHRH producing tumor of the hypothalamus, Ectopic tumor- Pancreas (V.V. rare) and others.

Diagnosis

IGF1 level (insulin like growth factor) is measured in serum - this is the best initial screening test.

Confirmation is done using glucose loading. 2hrs after Glucose loading the GH level should be suppressed in the normal person but not in acromegalics. (Read important principles of endocrinology)

One should scan the pituitary if the diagnosis is confirmed. These are usully macroadenomas thus can cause pressure related signs e.g. optic nerve compression.

30% of acromegalics have sleep apnea so a sleep study should be ordered.

Since GH is an antagonist of insulin, these patients can present with diabetes. They often have enlarged lower jaws leading to prognathism and malocclusion of teeth.

Since they have an accelerated growth of tissues, they have been found to have lesser regulated growth of cells and it is now well known that they have a 3 fold increased risk of colon cancer. One should do colonoscopy q 2yr. There is also a higher incidence of DM, DKA, Meningioma (esp. in pts who got XRT)

Management should aim for a normal level of IGF 1 in serum and GH <2ng (not 5) after oral glucose and normal circadian rhythm

Surgery- Trans-sphenoidal - not done if dura invalid Rxed

Microadenoma - cure 60-80%

Macroadenoma - cure 60%

XRT- long duration- cure rate 60% (may take 10 yrs), S/E- Pan hypopituitarism

Proton Beam- S/E increased Pan hypopituitarism

Gamma Knife- contraindicated in macroadenoma, useful in microadenoma- also gives quick results

Octreotide - 7 effect- injection- 100mg q 8

S/E- Gall stones in 30%. Cardiac arrhythmia, hypothyroidism

Most significant indicator of mortality is GH level. Not HT/DM/Cardiac Ds