Background: Several factors (bone age, BMI, target height, age) have been previously demonstrated to impact on GH response during stimulation tests, none of them proving to be of crucial importance.
Objective and hypotheses: To analyze the influence of several anthropometric and laboratory parameters on peak GH response during insulin and clonidine stimulation tests.
Method: Retrospective review of 265 patients who underwent GH stimulation tests with clonidine and/or insulin in two endocrinology centers (Bucharest and Tirgu-Mures) from Romania between 2009 and 2015. Variables: age, sex, height SD score, BMI SDS, and IGF1 SDS.
Results: Mean ages was 9.4±4.0 years with a sex repartition favoring boys (M: F=1.8:1). 165 subjects were GHD deficient according to the peak GH response (<10 ng/ml). In univariate analysis, BMI SDS was negatively correlated with peak GH during clonidine (r=(−0.20), P=0.0023), but not insulin (r=(−0.13), P=0.1776). IGF1 SDS correlates positively with both clonidine and insulin GH peak response (r=0.37 and 0.30, P<0.0001 and 0.0014 respectively). Age, sex and prepubertal status had no significant influence on the peak GH response. In multivariate regression analysis, BMI SDS and IGF1 SDS significantly influenced the peak GH response during clonidine, the whole model explaining 11.3% of the response. For insulin, the model explained 31.5% of the GH variance with age and IGF1 SDS being the significant factors.
Conclusion: In our study BMI SDS negatively correlates with GH response during clonidine, but not insulin GH stimulation test. IGF1 SDS is the only factor positively correlated with GH response in both provocative tests analyzed.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology