ESPE Abstracts

Background: The efficacy of growth hormone (GH) treatment in short, healthy children diagnosed with growth hormone deficiency (GHD) or those meeting the criteria of idiopathic short stature (ISS) suggest that an overlap exists between these two conditions. Although flawed and inconsistent, growth hormone stimulation tests (GHST) are the key diagnostic tool differentiating between GHD and ISS affecting clinical decisions such as treatment eligibility and dose.

Aim: To compare the response to GH treatment in children diagnosed as GHD or ISS based on their GHST

Methods: A single-center, retrospective study evaluating the response to GH treatment over 3 years in children diagnosed with GHD or ISS. GHD was defined as Peak GH<7.5ng/m in 2 GHST. The response to GH treatment was analyzed by mixed and linear models, in which the children were stratified according to their pubertal status and gender, and the GH dose was adjusted to body weight.

Results: 291 children (mean age 8.92.37; 38.8% females; 77.6% prepubertal) were included in the study. Height (Ht)-SDS significantly improved in all the children during the 3 years of GH treatment (P<0.001). In prepubertal children, Ht-SDS at baseline and along the treatment was comparable between the GHD and ISS groups (Pgroup), and the changes in Ht-SDS were similar along GH treatment (Ptime*group). In pubertal boys, Ht-SDS was lower at baseline and along treatment in the ISS compared to the GHD group (P<0.001) and comparable between the groups in pubertal girls. The changes in Ht-SDS were similar in pubertal boys and girls along GH treatment (Ptime*group). The response to GH treatment was also analyzed according to peak GH in the GHST by dividing the cohort into 3 groups: peak GH<6, 6GH<7.5, and GH7.5ng/ml, respectively, and was comparable between the groups.

Conclusions: The response to GH treatment is similar in healthy children defined as GHD or ISS based on GHST. These results suggest that the pivotal role of GHST in diagnosing and treating short children should be reconsidered.