title: The arginine stimulation test: timing of peak is not a helpful parameter in the diagnosis of growth hormone deficiency.
abstract: BACKGROUND
  A typical peak timing in the glucagon stimulation test has been reported as an indication of growth hormone (GH) deficiency. Other stimulation tests have not been evaluated.
  
  
  OBJECTIVE
  To evaluate the clinical usefulness of peak timing in the arginine stimulation test (AST) for growth hormone deficiency.
  
  
  METHODS
  Retrospective review of 199 ASTs from one center. Outcomes included correlation of peak times with (a) frequency of deficient peak; (b) growth velocity standard deviation scores (GVSDSs); (c) other evidence of pituitary pathology; (d) results of confirmatory clonidine test; and (e) response to GH treatment.
  
  
  RESULTS
  The peak in 83/109 (76.14%) sufficient tests occurred at typical times vs. 45/72 (62.5%) deficient tests (p<0.05). GVSDS on GH treatment was greater among patients with typical timing in the AST compared with atypical timing (2.67 ± 0.59 vs. 0.46 ± 1.17, p=0.021). No other variable correlated significantly with AST timing.
  
  
  CONCLUSIONS
  Timing of peak in the AST is not a clinically useful parameter.
authors.forename: David
authors.initials: D
authors.lastname: Gillis
authors.forename: Nadav
authors.initials: N
authors.lastname: Granat
authors.forename: David
authors.initials: D
authors.lastname: Strich
mesh_terms: D000293:Adolescent; D041923:Adolescent Development / Q000187:drug effects; D000728:Androgens / Q000494:pharmacology; D001120:Arginine / Q000008:administration & dosage; D002648:Child; D002657:Child Development / Q000187:drug effects; D002675:Child, Preschool; D015331:Cohort Studies; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D020249:Hormone Replacement Therapy; D019382:Human Growth Hormone / Q000097:blood / Q000172:deficiency* / Q000378:metabolism / Q000627:therapeutic use; D006801:Humans; D007018:Hypopituitarism / Q000175:diagnosis* / Q000188:drug therapy; D007223:Infant; D007262:Infusions, Intravenous; D007700:Kinetics; D008297:Male; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D000728:Androgens; D004967:Estrogens; D019382:Human Growth Hormone; D001120:Arginine