MON-113 The Effect of Body Mass Index on the Peak Growth Hormone Level After Growth Hormone Stimulation Test in Children with Short Stature

Objective: The aim of this study is to evaluate the effect of body mass index (BMI) on peak growth hormone (GH) response after GH stimulation test in children with short stature. Methods: Data was obtained from retrospective review of medical records who visited the pediatric endocrinology at St. Vincent hospital of catholic university for short stature from January 2010 to June 2019. We studied 115 children (aged 3-17 years old) whose height was less than 3percentile for one’s age and sex and who underwent GH stimulation test {GH deficiency (GHD) = 47, Idiopathic short stature (ISS) = 68)}. Peak GH response was stimulated by dopamine (n=111), clonidine (n=7), glucagon (n=19), insulin (n=56) and arginine (n=32). Birth weight, parental height, chronologic age, bone age, height SDS (standard deviation score), weight SDS, BMI SDS hemoglobin, fT4, T3 TSH, cortisol, ACTH, GH, IGF-1 SDS, IGF-BP3 SDS and peak stimulated GH were analyzed. Results: In the characteristics of subject, weight SDS and BMI SDS in GHD group were increased than ISS group (p<0.000, p=0.000). Free T4 was decreased in GHD group than ISS group (p=0.012). In total group, BMI SDS was associated negatively with peak GH level stimulated by dopamine (r=-0.419, p<0.000), insulin (r=-0.271, p=0.044) and arginine (r=-0.368, p=0.038), but did not showed correlation with peak GH level stimulated by glucagon. In GHD group, BMI SDS showed negative correlation with peak GH level using dopamine (r=-0.356, p=0.015) and arginine (r=-0.509, p=0.022). In ISS group, BMI SDS was correlated negatively with peak GH using dopamine (r=-0.330, p=0.007). In multivariate regression analysis of GHD group, weight SDS and BMI SDS were the only two significant predictors of peak GH response in stimulation test stimulated by dopamine (ß=-0.576, p=0.015) and arginine (ß=-0.097, p=0.022). In ISS group, only mother’s height (ß=0.474, p=0.000) and TSH (ß=-2.251, p<0.000) were demonstrated statistically significant predictors of peak GH stimulated by dopamine in multivariate regression analysis. In case of using insulin as a stimulant in ISS group, there is nothing which has statistical significance as a predictor of peak GH response in multivariate regression analysis. Conclusion: BMI was associated negatively with peak GH response after GH stimulation test in children with short stature, especially in GHD group.