title: Similar clinical features among patients with severe adult growth hormone deficiency diagnosed with insulin tolerance test or arginine or glucagon stimulation tests.
abstract: OBJECTIVE
  To determine whether insulin tolerance tests (ITTs), arginine stimulation tests (ASTs), and glucagon stimulation tests (GST) identify patients who have similar clinical features of growth hormone (GH) deficiency when a diagnostic GH threshold of 3 μg/L is used.
  
  
  METHODS
  Data were obtained from the KIMS database (Pfizer International Metabolic Database). Comparisons were made between patients who underwent ITT, AST, or GST for GH peak, body mass index, lipids, waist circumference, waist-to-hip ratio, and quality of life.
  
  
  RESULTS
  A total of 5453 tests were available from 4867 patients registered in the database (ITT = 3111, AST = 1390, GST = 952). Significant (P<.001) intraindividual correlations were observed between the GH peaks for ITT vs AST (r = 0.655), ITT vs GST (r = 0.445), and AST vs GST (r = 0.632). GH peaks in response to all tests were negatively correlated to the number of additional pituitary hormone deficiencies and positively correlated to the insulinlike growth factor 1 standard deviation score. Body mass index had a negative influence on all 3 tests. Most clinical variables did not differ between the groups when comparing GH-deficient patients according to the diagnostic test used. The only exceptions that showed any difference were body mass index (slightly higher in the AST and GST groups), triglyceride levels (increased in the GST group), and insulinlike growth factor 1 (standard deviation score) (lower in the ITT and AST groups than in the GST group). Waist circumference was greater and quality of life was worse in the GST group than in the other groups.
  
  
  CONCLUSIONS
  The ITT, AST, and GST produce similar GH peaks, are influenced by similar clinical factors, and identify patients with similar features of GH deficiency at a diagnostic threshold of 3 μg/L.
authors: Department of Endocrinology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom. andrew.toogood@uhb.nhs.uk
authors: Andrew
authors: A
authors: Toogood
authors: Georg
authors: G
authors: Brabant
authors: Dominique
authors: D
authors: Maiter
authors: Björn
authors: B
authors: Jonsson
authors: Ulla
authors: U
authors: Feldt-Rasmussen
authors: Maria
authors: M
authors: Koltowska-Haggstrom
authors: Ase Krogh
authors: AK
authors: Rasmussen
authors: Michael
authors: M
authors: Buchfelder
authors: Bernhard
authors: B
authors: Saller
authors: Beverly M K
authors: BM
authors: Biller
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001120:Arginine; D015992:Body Mass Index; D016208:Databases, Factual; D003940:Diagnostic Techniques, Endocrine; D005260:Female; D005934:Glucagon; D020249:Hormone Replacement Therapy; D019382:Human Growth Hormone / Q000097:blood / Q000172:deficiency* / Q000378:metabolism / Q000627:therapeutic use; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D017891:Pharmacoepidemiology / Q000379:methods; D011994:Recombinant Proteins / Q000627:therapeutic use; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D011994:Recombinant Proteins; D019382:Human Growth Hormone; D005934:Glucagon; D001120:Arginine