Though insulin-like growth factor-2, which originates in the liver, does exist, one must not confuse it with insulin-like growth factor-1. In fact, insulin-like growth factor-2 has to do with growth of the fetus in pregnant women but no connection with acromegaly. There is good reason to obtain a blood test for insulin-like growth factor-1 in patients who may have acromegaly. However, laboratory assays for insulin-like growth factor-2 have no benefit for the evaluation of patients with that disease [1, 2].
Some patients will benefit from a growth hormone suppression test in which the physician administers 75 grams of oral glucose two hours before the laboratory staff draws blood to measure the level of growth hormone. The diagnosis of acromegaly is present when this test does not suppress growth hormone level in the blood. In other words, suppression is the body’s normal response to administration of oral glucose [1, 2].
Magnetic resonance imaging is a sensitive method that may identify the presence of a pituitary adenoma. In fact, it can detect an adenoma as small as two millimeters in diameter. It is important to assess the client’s kidney function prior to the performance of this test as the contrast material poses a contraindication when there is impairment of renal function [1, 2].
Of course, there are many hormonal assays to determine how well the endocrine system operates. Some of these include measurement of thyroid-stimulating hormone, thyroxine, follicle-stimulating hormone, cortisol, luteinizing hormone, testosterone, and prolactin [1, 2].
Moreover, a visit to the ophthalmologist is especially important as these patients may suffer from visual defects. This happens because nerve fibers that cross in the brain—at the optic chiasm—function improperly because the adenoma exerts pressure there.