title: The effectiveness of arginine + GHRH test compared with GHRH + GHRP-6 test in diagnosing growth hormone deficiency in adults.
abstract: OBJECTIVE
  The objective of this study is to investigate the performance of two novel tests in diagnosing growth hormone deficiency in adults.
  
  
  METHODS
  Fifty patients presenting with long-standing hypopituitarism and two control groups consisting of 50 healthy subjects in each group [age-, sex- and body mass index (BMI)-matched] participated in a multicentre study. All underwent two provocative tests on different days within 3 months apart: (i) a combined GHRH + GHRP-6 test and (ii) arginine + GHRH test. Main outcome measures were sensitivity, specificity and areas under receiver operating characteristic curves (ROC) for GHRH + GHRP-6 and arginine + GHRH tests in the diagnosis of GH deficiency in adults.
  
  
  RESULTS
  A peak GH level after GHRH + GHRP-6, under 15.0 microg/l had a sensitivity of 94.4% and specificity of 98.8% for diagnosing GHD and area under the ROC curve was 0.99 (95% confidence interval 0.95-0.99). For peak GH levels after arginine + GHRH, a level under 9.6 microg/l had a sensitivity of 88.4% and specificity of 95% and area under the ROC curve of 0.96 (95% confidence interval 0.91-0.98). The relationship between the increment in serum GH following GHRH + GHRP-6 and arginine + GHRH test was positive, i.e. r = 0.749, P = 0.001.Thus, there was high concordance between both tests.
  
  
  CONCLUSIONS
  Both GHRH + GHRP-6 and/or arginine + GHRH test may serve as an alternative to the ITT in diagnosing GHD in adults.
authors.affiliation: Institute of Endocrinology, Diabetes and Diseases of Metabolism, University Clinical Center, Belgrade, Yugoslavia. popver@eunet.yu
authors.forename: Vera
authors.initials: V
authors.lastname: Popovic
authors.forename: Sandra
authors.initials: S
authors.lastname: Pekic
authors.forename: Mirjana
authors.initials: M
authors.lastname: Doknic
authors.forename: Dragan
authors.initials: D
authors.lastname: Micic
authors.forename: Svetozar
authors.initials: S
authors.lastname: Damjanovic
authors.forename: Milos
authors.initials: M
authors.lastname: Zarkovic
authors.forename: Gianluca
authors.initials: G
authors.lastname: Aimaretti
authors.forename: Ginerva
authors.initials: G
authors.lastname: Corneli
authors.forename: Ezio
authors.initials: E
authors.lastname: Ghigo
authors.forename: Carlos
authors.initials: C
authors.lastname: Deiguez
authors.forename: Felipe F
authors.initials: FF
authors.lastname: Casanueva
mesh_terms: D000328:Adult; D000368:Aged; D001120:Arginine; D016022:Case-Control Studies; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis*; D013006:Growth Hormone / Q000097:blood* / Q000172:deficiency*; D013007:Growth Hormone-Releasing Hormone; D006801:Humans; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D009842:Oligopeptides; C041048:growth hormone releasing hexapeptide; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D001120:Arginine