Related Experiment Videos
First-phase insulin release in normal children
H F Allen1, B W Jeffers, G J Klingensmith
1Department of Pediatrics, University of Colorado Health Sciences Center, Denver 80262.
Insights
First-phase insulin release is lower in children than adolescents. This study defines normal values for first-phase insulin release during an intravenous glucose tolerance test in healthy youth.
Area of Science:
- Pediatrics
- Endocrinology
- Metabolic Research
Background:
- Normal values for first-phase insulin release (FPIR) in youth are not well-established.
- Understanding FPIR is crucial for assessing pancreatic beta-cell function.
- Variations in FPIR can indicate underlying metabolic or endocrine conditions.
Purpose of the Study:
- To define normal ranges for FPIR during an intravenous glucose tolerance test (IVGTT) in healthy children and adolescents.
- To investigate the relationship between age, pubertal status, and FPIR.
- To assess the impact of acute stress on FPIR.
Main Methods:
- A standard intravenous glucose tolerance test (IVGTT) was administered to 69 healthy subjects aged 7 to 22 years.
- Subjects were screened for family history of type I diabetes, normal glycohemoglobin, and negative islet cell antibodies.
- FPIR was measured, and intraindividual variability was assessed in a subset of subjects.
Main Results:
- Mean FPIR significantly increased with age and pubertal status.
- FPIR values were 93 +/- 10.1 mIU/L (7-10 years), 172.7 +/- 22.3 mIU/L (11-15 years), and 163 +/- 28.5 mIU/L (16-22 years).
- Acute stress did not show a significant correlation with FPIR.
Conclusions:
- First-phase insulin release is markedly lower in prepubertal children compared to adolescents and young adults.
- Age and pubertal status are key determinants of normal FPIR values in youth.
- These findings provide essential reference ranges for pediatric endocrinology and diabetes research.
Abstract:
Normal values for the first-phase insulin release during an intravenous glucose tolerance test are not yet well defined for children and adolescents. In this study, 69 normal subjects (aged 7 to 22 years) who had no family history of type I diabetes, a normal glycohemoglobin value, and a negative islet cell antibody test result underwent a standard intravenous glucose tolerance test. The mean (+/- SEM) first-phase insulin release increased with age and pubertal status: 7 to 10 years, 93 +/- 10.1 mIU/L; 11 to 15 years, 172.7 +/- 22.3 mIU/L; and 16 to 22 years, 163 +/- 28.5 mIU/L. The mean intraindividual variability in 11 subjects who underwent a second test was 23.6%. Acute stress, as estimated by observer assessment or by blood catecholamine levels, did not significantly correlate with first-phase insulin release. We conclude that first-phase insulin release is markedly lower in prepubertal children than in adolescents and young adults.