ESPE Abstracts

Introduction: Glucagon serves as a growth hormone (GH) secretagogue. Serial measurements of GH concentration following glucagon administration are one of the growth hormone stimulation tests (GHSTs) for assessing GH sufficiency in children with suspected growth hormone deficiency (GHD). Although intramuscular glucagon is utilized to evaluate GH secretion, the relationship between changes in blood glucose (BG) and GH during this test has not been thoroughly studied.

Objectives: To investigate the changes in GH concentrations in relation to BG levels before and after glucagon injection in children with short stature.

Patients and Methods: A standard glucagon stimulation test was conducted in 42 children aged 6-11 yrs (mean 9.5+/-2 yrs) with short stature, defined as height standard deviation scores (HtSDS) less than -2. Plasma glucose and GH levels were determined at baseline and at 30, 60, 90, 120, 150, and 180 minutes after intramuscular injection of 0.1 mg/kg glucagon.

Results: No side effects were reported during the procedure. Asymptomatic hypoglycemia (< 2.8 nmol/L) occurred in 4 of the 42 children at least once between 90 and 120 minutes. Hyperglycemia (BG > 150 mg/dL) was noted in 6 children at 60 minutes post-injection. Peak GH concentrations of less than 7 micrograms/L were observed in 13 of the 42 children. The highest mean glucose concentration was recorded at 60 minutes, and the lowest at 120 minutes post-glucagon. A significant negative correlation between glucose and GH concentrations was observed at 60 minutes (Spearman's Rs=−0.32; P <0.01), with a positive correlation at 120 minutes (Rs= 0.31; P = 0.01).

Discussion: The data suggest that a decrease in mean BG concentration from its peak at 60 minutes to a nadir at 120 minutes correlates with significant changes in GH levels. A lower GH level was associated with a relatively higher BG at 60 minutes, and higher GH levels corresponded with the lowest BG at 120 minutes.

Conclusion: This inverse relationship between BG and GH at the peak glucose time point, and the direct relationship as glucose levels decreased, provides insights into the glucose-GH dynamics during glucagon stimulation tests in short-stature children.