Endocrine Abstracts

JOINT2187

Background: Insulin-like growth factor-1 (IGF-1) is widely recognized as a key parameter for monitoring the therapeutic effects of rhGH and guiding treatment adjustments. However, the majority of growth responses are influenced by the concentration differences between IGF-1 and IGFBP-3. For biologically active substances, the molar ratio of IGF-1/IGFBP-3 more accurately reflects changes in biological activity. Therefore, this study aims to investigate the value of the IGF-1/IGFBP-3 molar ratio in assessing the therapeutic efficacy of rhGH.

Methods: This study included 67 children with short stature who received recombinant human growth hormone (rhGH) treatment. Participants were categorized into three groups based on etiology: growth hormone deficiency (GHD) (n = 18), idiopathic short stature (ISS) (n = 37), and small for gestational age (SGA) (n = 12). The primary outcome measures included the changes in IGF-I SDS and the IGF-I/IGFBP-3 molar ratio SDS at baseline and at 3, 6, 9, and 12 months post-treatment, as well as their correlation with the rhGH treatment dose and changes in height SDS. The treatment effect was also evaluated (a ΔHt-SDS ≥ 0.5 SDS increase in height standard deviation within 1 year of treatment was considered a good treatment effect).

Results: After one year of rhGH treatment, all groups showed significant increases in IGF-1 SDS, IGF-1/IGFBP-3 molar ratio SDS, and height SDS compared to baseline (P <0.05). During the treatment period, rhGH dose was positively correlated with both IGF-1 SDS (r = 0.773, P <0.001) and IGF-1/IGFBP-3 molar ratio SDS (r = 0.843, P <0.001). The trends in IGF-1 SDS and IGF-1/IGFBP-3 molar ratio SDS paralleled those in height SDS. Among the 46 patients with a good treatment response, the IGF-1/IGFBP-3 molar ratio SDS was significantly higher compared to those with a poor response (P <0.01).

Conclusion: The molar ratio of IGF-1/IGFBP-3 is an important biomarker for evaluating the therapeutic effect of growth hormone and provides a theoretical basis for formulating individualized clinical treatment strategies.

Key words: Growth hormone deficiency; Small for gestational age; Idiopathic short stature; Recombinant human growth hormone; Molar ratio of IGF-1/IGFBP-3