ESPE Abstracts

Introduction: Growth hormone (GH) stimulation tests are essential tools for diagnosing growth hormone deficiency (GHD) as a serum peak GH level less than 10 µg/L on two separate tests. We aim ed to compare L-dopa, insulin, and arginine-induced stimulation tests based on the response to GH replacement.

Methods: We retrospectively collected data from a review of patients who underwent the GH stimulation test. A total of 155 patients diagnosed with idiopathic short stature (ISS) were categorized into group I. The remaining 149 patients, diagnosed with GHD and treated for one year, were classified into two subgroups: group IIa, comprising patients with an increase of at least 0.5 in height standard deviation score (SDS), and group IIb, patients with an increase of less than 0.5 in height SDS.

Results: At the initial visit, group IIa exhibited significantly lower IGF-BP3 and higher BMI SDS compared to the other groups. Following one year of treatment, group IIb showed significantly lower height SDS, increase in height SDS, height increase velocity, predicted adult height SDS, weight SDS, BMI SDS, and a higher IGF-1 SDS than group IIa. Bone age was inversely associated, and BMI SDS was positively associated with height SDS gain in GHD patients. The specificity and accuracy rates were 48.9% and 69.4% for the L-dopa induced stimulation test, 75.0% and 87.4% for insulin tolerance test (ITT) and 64.9% and 87.5% for arginine-induced stimulation test (AST).

Conclusion: The AST demonstrated lower specificity compared to the ITT. However, patients undergoing AST experienced fewer side effects and were not at risk, suggesting that a careful selection of stimulation tests is crucial in diagnosing GHD.