Testing growth hormone deficiency in adults

Abstract

Growth hormone deficiency (GHD) in adults is a recognized syndrome which is defined biochemically within an appropriate clinical context. Clinically, patients investigated for GHD should include those with signs and symptoms of hypothalamic-pituitary disease, those who have received cranial irradiation or tumor treatment and those with traumatic brain injury or subarachnoid hemorrhage. Patients with three or more pituitary hormone deficiencies and an IGF-I below the reference range do not require provocative testing. The other patients need a provocative test of GH secretory reserve for the diagnosis of GHD. Insulin tolerance test is considered the diagnostic test of choice, however, the GH-releasing hormone (GHRH)+arginine, the GHRH+growth hormone-releasing peptide and the glucagon stimulation tests are well validated alternative tests in adults. Cutoffs differ across tests and results may be influenced by gender, age, body mass index, and the assay reference preparation.