New guidelines for the diagnosis of growth hormone deficiency in adults

The task of diagnosing growth hormone deficiency (GHD) in adults is cumbersome because of the paucity of biological endpoints. Consequently, over the past decade different organizations have attempted to develop homogeneous criteria and methodology for worldwide use. GHD should be biochemically confirmed within an appropriate clinical context - but only if there is the intention to treat. Clinically, patients investigated for GHD should include those with signs and symptoms or a past history of hypothalamo-pituitary dysfunction and those with a history of cranial irradiation, tumour treatment, traumatic brain injury or subarachnoid haemorrhage.

Subjects with >/=3 pituitary hormone deficiencies plus a low insulin-like growth factor I level do not need provocative testing. For those who must be tested, arguably the most commonly used provocative tests are the insulin tolerance test and the glucagon, GH-releasing hormone (GHRH) + arginine and GHRH + GH-releasing hexapeptide tests. Cutoffs differ across tests and results may be influenced by gender, age, body mass index and the assay reference preparation.