Brain MRIs may be of low value in most children diagnosed with isolated growth hormone deficiency

Objectives Brain MRIs are considered essential in the evaluation of children diagnosed with growth hormone deficiency (GHD), but there is uncertainty about the appropriate cut-off for diagnosis of GHD and little data about the yield of significant abnormal findings in patients with peak growth hormone (GH) of 7–10 ng/mL. We aimed to assess the frequency of pathogenic MRIs and associated risk factors in relation to peak GH concentrations. Methods In this retrospective multicenter study, charts of patients diagnosed with GHD who subsequently had a brain MRI were reviewed. MRIs findings were categorized as normal, incidental, of uncertain significance, or pathogenic (pituitary hypoplasia, small stalk and/or ectopic posterior pituitary and tumors). Charges for brain MRIs and sedation were collected. Results In 499 patients, 68.1% had normal MRIs, 18.2% had incidental findings, 6.6% had uncertain findings, and 7.0% had pathogenic MRIs. Those with peak GH<3 ng/mL had the highest frequency of pathogenic MRIs (23%). Only three of 194 patients (1.5%) with peak GH 7–10 ng/mL had pathogenic MRIs, none of which altered management. Two patients (0.4%) with central hypothyroidism and peak GH<4 ng/mL had craniopharyngioma. Conclusions Pathogenic MRIs were uncommon in patients diagnosed with GHD except in the group with peak GH<3 ng/mL. There was a high frequency of incidental findings which often resulted in referrals to neurosurgery and repeat MRIs. Given the high cost of brain MRIs, their routine use in patients diagnosed with isolated GHD, especially patients with peak GH of 7–10 ng/mL, should be reconsidered.

Association between triglyceride glucose index and peak growth hormone in children with short stature

Growth hormone (GH) secretion is related to many factors, such as weight and puberty, and the reproducibility of GH provocation tests is very poor. This study aimed to evaluate whether the triglyceride (TyG) index was associated with peak GH in children with short stature. This study included 1095 children with short stature divided into two groups based on peak GH level in GH provocation tests [GH deficiency (GHD) group = 733 children; non-GHD group = 362 children]. We found that the TyG index was significantly higher in the GHD group than in the non-GHD group (P < 0.001). A nonlinear relationship was detected between the TyG index and peak GH, whose point was 7.8. A significant negative association between the TyG index and peak GH was observed when the TyG index was greater than 7.8 (β − 2.61, 95% CI − 3.98, − 1.24; P < 0.001), whereas, the relationship between the TyG index and peak GH was not significant when the TyG index was lower than 7.8 (β 0.25, 95% CI − 1.68, 2.17; P = 0.799). There is a nonlinear relationship between the TyG index and peak GH, and a higher TyG index is associated with decreased peak GH in children with short stature.

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&lt;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&lt;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&lt;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.