Biochemical markers of acromegaly: GH vs. IGF-I.

The development of sensitive and specific growth hormone (GH) and insulin-like growth factor I (IGF-I) assays opened a new page in the diagnosis and surveillance of acromegaly. Currently, it is possible to make an accurate pre-operative diagnosis even in patients with virtually no typical clinical signs of the disease and to monitor the efficacy of therapeutic intervention with a high degree of precision. This review briefly discusses the performance parameters of GH and IGF-I as diagnostic and surveillance tools in patients with acromegaly. In brief, whereas GH-based parameters may offer the advantage of disclosing dysregulation of GH secretion, a single plasma IGF-I measurement provides the most comprehensive assessment of both the overall GH output as well as the pattern of GH presentation to the peripheral tissues. Judicious use of both biochemical markers allows accurate and early diagnosis, precise assessment of the efficacy of therapeutic interventions, permits adjustment in the dose of medication and allows for unequivocal demonstration of a final cure.