Related Experiment Video
Updated: Jan 20, 2026
Author Spotlight: Repetitive Transcranial Magnetic Stimulation Combined with Movement Observation in Cerebral Palsy
Published on: August 9, 2024
Peak Growth Hormone Response to Combined Stimulation Test in 315 Children and Correlations with Metabolic Parameters
Mabel Yau1, Elizabeth Chacko2, Molly O Regelmann3
1Division of Pediatric Endocrinology and Diabetes, Icahn School of Medicine at Mount Sinai, New York, New York, USA, mabel.yau@mssm.edu.
Insights
Peak growth hormone (PGH) response to arginine and levodopa (A-LD) typically occurs by 120 minutes. Body mass index (BMI) negatively impacts PGH, suggesting adjustments in growth hormone stimulation testing interpretation.
Area of Science:
- Pediatric Endocrinology
- Growth Hormone Physiology
- Metabolic Health
Background:
- Limited data exists on the precise timing of peak growth hormone (PGH) response following stimulation.
- Understanding factors influencing PGH is crucial for accurate diagnosis of growth disorders.
Purpose of the Study:
- To determine the timing of PGH response to arginine and levodopa (A-LD) stimulation.
- To investigate the impact of body mass index (BMI) and metabolic parameters on PGH.
Main Methods:
- Growth hormone (GH) stimulation testing (ST) using A-LD was performed in 315 children.
- Serum GH levels were measured at baseline and every 30 minutes up to 180 minutes.
- IGF-1, IGF BP3, BMI, and metabolic markers were assessed at baseline.
Main Results:
- 97.8% of children exhibited peak GH response at or before 120 minutes.
- GH area under the curve (AUC) positively correlated with PGH and IGF-1 (in pubertal subjects).
- BMI showed a negative correlation with PGH, while GH AUC negatively correlated with HOMA-IR and total cholesterol.
Conclusions:
- GH ST with A-LD can be terminated at 120 minutes without affecting diagnosis of GH deficiency (cut-off <10 ng/mL).
- BMI is a significant factor to consider when interpreting A-LD GH ST results.
- Further research is needed to explore the relationship between GH AUC and metabolic parameters.
Background/Aims:
Studies are lacking regarding the timing of peak growth hormone (PGH) response. We aim to elucidate the timing of PGH response to arginine and levodopa (A-LD) and evaluate the influence of body mass index (BMI) and other metabolic parameters on PGH.
Methods:
During growth hormone (GH) stimulation testing (ST) with A-LD, serum GH was measured at baseline and every 30 min up to 180 min. The PGH cut-off was defined as <10 ng/mL. IGF-1, IGF BP3, BMI, and metabolic parameters were obtained in a fasting state at baseline.
Results:
In the 315 tested children, stimulated PGH levels occurred at or before 120 min in 97.8% and at 180 min in 2.2%. GH area under the curve (AUC) positively correlated with PGH in all patients and with IGF-1 in pubertal males and females. BMI negatively correlated with PGH in all subjects. GH AUC negatively correlated with HOMA-IR and total cholesterol.
Conclusion:
We propose termination of the GH ST with A-LD at 120 min since omission of GH measurement at 180 min did not alter the diagnosis of GH deficiency based on a cut-off of < 10 ng/mL. BMI should be considered in the interpretation of GH ST with A-LD. The relationships between GH AUC and metabolic parameters need further study.
More Related Videos
Related Concept Videos
07:20Repeated Transcranial Magnetic Stimulation Combined with Action Observation Training in Children with Spastic Cerebral Palsy
14:47Combined Peripheral Nerve Stimulation and Controllable Pulse Parameter Transcranial Magnetic Stimulation to Probe Sensorimotor Control and Learning
11:01Monitoring Plant Hormones During Stress Responses
02:13Types of Hormones
01:56Plant Hormones
01:40Hormonal Regulation