A practical approach to the diagnosis of growth hormone (GH) deficiency in patients transitioning to adulthood using GH stimulation testing.
To establish the diagnosis of adult growth hormone deficiency (GHD), GH-deficient children transitioning to adulthood are evaluated by two separate stimuli 2 or more weeks after ceasing GH therapy. While 20-88% of children diagnosed with idiopathic GHD retest with normal values, those with proven genetic defects in GH production/secretion/bioactivity and patients with panhypopituitarism consistently test deficient. The US Food and Drug Administration (FDA) defines GHD in adults by stimulated peak serum GH concentrations <5 ng/ml if measured by polyclonal radioimmunoassays (RIA) or lower if measured by monoclonal assays. Some investigators define severe GHD by a peak GH concentration <3 ng/ml. Adult responses to arginine and glucagon testing are similar to the responses to insulin tolerance testing; clonidine, pyridostigmine, and galanin cause lesser peaks of GH. Growth hormone-releasing hormone (GHRH) combined with arginine, GH releasing peptide-6 (GHRP-6), or hexarelin leads to higher peak responses than GHRH alone. Thus the choice of testing methods impacts the diagnosis of GHD in transition patients.
Styne
Dennis M
DM
Department of Pediatric Endocrinology, University of California Davis School of Medicine, Sacramento, CA 95817, USA. dmstyne@ucdavis.edu
D000293:Adolescent; D016497:Adolescent Health Services; D000328:Adult; D017668:Age of Onset; D002648:Child; D019937:Diagnostic Techniques and Procedures / Q000592:standards; D006130:Growth Disorders / Q000175:diagnosis; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000172:deficiency* / Q000627:therapeutic use; D006801:Humans; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D019382:Human Growth Hormone