ESPE Abstracts

Background: It is well-known that human GH (hGH) treatment increases growth rate in idiopathic short stature (ISS) in the short term which might predict the overall height gain. However,the fact that ISS might involve a heterogeneous group of individuals with individual benefits from hGH treatment makes the decision to treat or not to treat difficult.

Objective and hypotheses: The aim of this study was to investigate retrospectively whether an IGF1 generation test (IGFGT) might be used as a tool to predict the first year growth response to GH treatment in individuals with ISS.

Method: 57 subjects with ISS who had at least %20 increase in IGF1 levels with an IGFGT and who were treated for at least one whole year with GH were included in the study. Of these 57 subjects, 29 were girls. The mean age of the patients was 11.47±1.95 years and 38 were prepubertal. IGF1 levels were measured by a chemiluminescence immunoassay. IGF1 levels and heights were expressed as SDS both for age and gender. Bone age was evaluated by Greulich Pyle method. The increase in IGF1 levels were expressed both as the percentage of the initial value and delta IGF SDS.

Results: Height SDS increased significantly both in pubertal (−2.78±0.88 vs −2.03±0.80) and prepubertal (−2.77±0.54 vs −2.50±0.64) subjects; however, bone age increased 2.12±1.54 years and 2.00±1.32 years in 1 year respectively. There was a negative correlation between delta height SDS and basal IGF1 SDS (r=−0.434, P=0.001). There was a positive correlation between delta height SDS and delta IGF1 SDS (r=0.372, P=0.004) but the same was not true for percentage increase in IGF1.

Conclusion: Our results suggest that in individuals with ISS, the lower basal IGF1 SDS is and the higher increase in IGF1 SDS(in an IGFGT) is, the more the height gain after one year of GH treatment is.