Can Growth Hormone Stimulation Tests in Children Predict the Response to Growth Hormone Treatment?

Abstract

Objective: The efficacy of growth hormone (GH) treatment in short, healthy children diagnosed with growth hormone deficiency (GHD) or idiopathic short stature (ISS) suggests an overlap between these 2 conditions. Although imperfect and inconsistent, GH stimulation testing (GHST) remains the primary diagnostic tool for differentiating GHD and ISS, influencing GH treatment eligibility and dosing. This study aims to assess the clinical significance of GHST by comparing the response to GH treatment in children diagnosed with GHD or ISS based on their GHST results.

Methods: A retrospective study in an endocrine clinic at a tertiary pediatric referral center comparing the response to GH treatment over 3 years in children diagnosed with GHD or ISS.

Results: Two hundred ninty-one children treated with GH, 97 children diagnosed with GHD, and 194 with ISS are included in the analysis. Height significantly improved, and insulin-like growth factor-1 levels increased independent of the GHST results, gender, or pubertal status (P < .001). When adjusting for dosage, height gain was not associated with the treatment indication, GHD or ISS, or GHST peak levels.

Conclusions: Our findings indicate similar responses to GH treatment in children classified 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.

Keywords: Ht-SDS; IGF-1; ISS (idiopathic short stature); growth hormone; growth hormone deficiency (GHD); stimulation test.