Background: It is important to find and manage the cause of short stature in children. GH stimulation test is considered as a gold standard for the diagnosis of GH deficiency (GHD), and several pharmacologic agents including insulin, glucagon, L-dopa, or clonidine are used for GH stimulation test (GHST). However, diagnostic value, sensitivity or specificity of each GHST is not clear.
Objective and hypotheses: This study was designed to evaluate the diagnostic value of GHST by insulin, glucagon, L-dopa, or clonidine for GHD during childhood.
Method: Subjects who visited the pediatric endocrine clinic for the evaluation of short stature underwent GHST using two or three combinations out of insulin, glucagon, L-dopa, or clonidine. GH deficiency was defined when serum peak GH concentration was less than 10 ng/ml with at least two provocation tests. Clinical data were collected retrospectively from a review of 55 children who performed GHST for the evaluation of short stature between January 2011 and December 2014.
Results: A total of 38 children (69.1%) were diagnosed with GHD and 18 children (30.9%) were diagnosed with idiopathic short stature. Mean height z score was −2.52. Insulin test, glucagon test, L-dopa teat, and clonidine test were done in 54, 41, 45, and 12 subjects, respectively. In each test, sensitivity for GHD was 100, 65.4, 74.2, and 90%, respectively. Specificity was 56.3, 73.3, 92.9, and 50%, respectively. Positive predictive value for GHD was highest in L-dopa test (95.9%), and negative predictive value was highest in insulin test (100%). There was no serious adverse event during GHST, except for mild hypoglycemic symptoms or transient vomiting.
Conclusion: Any GHST was relatively safe to perform in short children. Considering the GHST results, we could conclude that combination test using insulin and clonidine is more useful to detect GHD in short children.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology