Diagnosis and endocrine testing in acromegaly

Acromegaly is a characteristic clinical syndrome resulting from excessive production of GH and SmC/IGF-I generally from a GH-producing pituitary tumor. Once the diagnosis is suspected on clinical grounds, it should be established based on persistent elevation of the basal GH, along with an increased SmC/IGF-I level; it is confirmed by a lack of suppressibility of GH levels following a glucose load. Other tests, including the paradoxic GH elevation in response to TRH and LHRH, are helpful in establishing the diagnosis, as well as determining and monitoring the outcome of surgical and medical therapy. The past few years have been enriched with new knowledge in the area of IGF-binding proteins. Evidence of clinical correlation exists regarding GH status, IGF-I levels, and the IGFBPs particularly IGFBP-1 and IGFBP-3. The value of IGFBPs in clinical practice as a diagnostic tool in disorders of GH secretion appears promising, but further studies are required.