Original Article

Evaluation of IGF1/IGFBP3 Molar Ratio as an Effective Tool for Assessing the Safety of GH Therapy in Small-for-Gestational-Age, GH-Deficient and Prader-Willi Children


  • Meriem Gaddas
  • Laurence Périn
  • Yves Le Bouc

Received Date: 28.11.2018 Accepted Date: 10.02.2019 J Clin Res Pediatr Endocrinol 0;0(0):0-0 [e-Pub] PMID: 30759961


IGF1 concentration is the most widely used parameter for the monitoring and therapeutic adaptation of recombinant human growth hormone (rGH) treatment. However, more than half the variation of the therapeutic response is accounted for by variability in the serum concentrations of IGF1 and IGFBP3. We therefore compared the use of IGF1/IGFBP3 molar ratio with that of IGF1 concentration alone.


We selected 92 children on rGH for this study and assigned them to three groups on the basis of growth deficiency etiology: small for gestational age (SGA), GH deficient (GHD) and Prader-Willi syndrome (PWS). Plasma IGF1 and IGFBP3 concentrations and their molar ratio were determined.


Before rGH treatment, mean IGF1/IGFBP3 molar ratio in the SGA, GHD and PWS groups was 0.14 ± 0.04; 0.07 ± 0.01 and 0.12 ± 0.02, respectively. After the initiation of rGH treatment, these averages were 0.19 ± 0.07, 0.20 ± 0.08 and 0.19 ± 0.09, within the normal range for most children, even at puberty and despite some significant increases in serum IGF1 levels.


We consider IGF1/IGFBP3 molar ratio to be a useful additional parameter for assessing therapeutic safety on rGH, keeping values within the normal range for age and pubertal stage.

Keywords: GH therapy, IGF1/IGFBP3 molar ratio, Growth Hormone Deficiency, Small for Gestational Age, Prader-Willi Syndrome