Evaluation of diagnostic accuracy of insulin-like growth factor (IGF)-I and IGF-binding protein-3 in growth hormone-deficient children and adults using ROC plot analysis

J Clin Endocrinol Metab. 2003 Oct;88(10):4702-8. doi: 10.1210/jc.2003-030412.

Abstract

We critically evaluated the diagnostic value of IGF-I and IGF-binding protein-3 (IGFBP-3) in GH deficiency (GHD) in children and adults using receiver operating characteristic (ROC) plot analysis. Sixty-six children (chronological age, 1.3-15 yr) were studied: 34 GHD and 32 idiopathic short stature (ISS). Ninety-two adults (chronological age, 18-70 yr) were also evaluated: 72 GHD, 34 of childhood onset (AGHD-CO), and 38 of adult onset (AGHD-AO); and 20 healthy volunteers. The SD score (SDS) for IGF-I was calculated from 596 normal subjects (212 children and 384 adults), and the SDS for IGFBP-3 was calculated from 350 normal subjects (212 children and 138 adults). The ROC plot showed that the best IGF-I SDS cut-off line was -1.65 for children [sensitivity (S), 68%; specificity (Sp), 97%, diagnostic efficiency (DEf), 81%], the cut-off line for AGHD was -1.65 for AGHD-CO (S, 91%; Sp, 100%; DEf, 94%), and the cut-off line for AGHD-AO was -1.80 (S, 81%; Sp, 100%; DEf, 88%). For IGFBP-3 SDS, the best cut-off line was -1.80 for children (S, 90%; Sp, 60%; DEf, 78%); it was -1.45 for AGHD-CO (S, 90%; Sp, 75%; DEf, 82%) and -0.90 for AGHD-AO (S, 90%; Sp, 68%; DEf, 77%). An accurate diagnosis was obtained using IGF-I SDS alone in GHD children 65%; ISS, 97%; AGHD-CO, 92%; AGHD-AO, 86%, with IGFBP-3 SDS alone in GHD children 60%; ISS, 90%; AGHD-CO, 75%; AGHD-AO, 68%. Considering both, an accurate diagnosis was obtained in GHD children 60%; ISS, 87%; AGHD-CO, 71%; AGHD-AO, 64%. In conclusion, our findings support the need to use cut-off lines expressed in SDS obtained using an appropriate statistical methodology for better characterization of the various clinical presentations. IGF-I proved to be more useful because of its good diagnostic efficiency and accuracy in both children and adults, whereas IGFBP-3 did not significantly contribute to the diagnosis of GHD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • Evaluation Studies as Topic
  • Female
  • Growth Disorders / blood*
  • Growth Disorders / diagnosis*
  • Human Growth Hormone / deficiency*
  • Humans
  • Immunoradiometric Assay / standards
  • Infant
  • Insulin-Like Growth Factor Binding Protein 3 / blood*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Middle Aged
  • ROC Curve*
  • Reference Values
  • Reproducibility of Results

Substances

  • Insulin-Like Growth Factor Binding Protein 3
  • Human Growth Hormone
  • Insulin-Like Growth Factor I