Elucidating the relationship between blood glucose dynamics and growth hormone responses in glucagon stimulation tests among children with short stature

Introduction: The use of glucagon as a provocative agent for growth hormone (GH) assessment is a cornerstone in pediatric endocrinology. Glucagon's role as a GH secretagogue is integral to growth hormone stimulation tests (GHSTs), which diagnose suspected GH deficiency (GHD) in children. These tests are crucial for assessing the hypothalamic-pituitary-adrenal (HPA) axis's integrity. Despite its prevalent use, the exact mechanisms by which glucagon prompts GH release and the impact of ensuing blood glucose (BG) fluctuations are not fully understood. Objectives: This study aims to explore the relationship between GH and BG levels in children with short stature following glucagon administration. Patients and Methods: A retrospective cohort study involved 42 pediatric patients, aged 6 to 11, with short stature. We analyzed GH and BG levels before and after intramuscular glucagon Simulation test (GST). Blood samples were taken at baseline and multiple intervals post-injection. Results: The results revealed that the mean glucose peaked at 60 minutes and declined to a nadir at 120 minutes, which corresponded with a significant rise in GH levels. GH concentrations peaked at 120 minutes post-injection, with 31% of children showing peak GH levels of less than 7 μg/L. Notably, the study found an inverse correlation between BG and GH at peak glucose times, suggesting a complex interplay between glucose dynamics and GH response. Discussion: Our findings indicate a dynamic interrelation between BG and GH post-glucagon injection, challenging traditional interpretations of GST results. The study reinforces the notion that GHST results should be interpreted with consideration of patient-specific factors such as BMI to ensure accurate evaluation of GH reserve and subsequent clinical decision-making. Conclusion: The study corroborates the dynamic nature of GH and glucose responses following glucagon administration and highlights the need for personalized approaches in interpreting GHSTs. Further investigation is warranted to elucidate the mechanisms influencing this complex relationship, which is crucial for accurate diagnosis and management of GHD in children.