How many tests are required to diagnose growth hormone (GH) deficiency in adults?

Abstract

We have demonstrated that a constant ratio links the GH response to an ITT and AST in an individual, rather than a constant difference, and that the difference between the GH responses to two provocative stimuli is greater in those patients with milder degrees of GH deficiency or insufficiency. These patients tend to have one or no additional pituitary hormone deficits and may be misclassified if a single GH provocative test is performed. We suggest that whilst a single GH provocative test can be used with confidence in patients with two or three additional pituitary hormone deficits, in patients with suspected isolated GH deficiency or with only one additional pituitary hormone deficit, two GH provocative tests should be performed.