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B-cell response to exercise in diabetic and non-diabetic children
Insights
Exercise impacts insulin dynamics differently in children. Non-diabetic children showed decreased insulin markers during exercise, while insulin-dependent diabetic children experienced a fall in endogenous insulin secretion.
Area of Science:
- Endocrinology
- Pediatric Metabolism
- Exercise Physiology
Background:
- Understanding the metabolic response to exercise is crucial for managing diabetes in children.
- Insulin-dependent diabetic (IDD) children have unique physiological challenges during physical activity.
- The interplay between glucose, insulin, C-peptide, and proinsulin during exercise requires further elucidation.
Purpose of the Study:
- To investigate the acute effects of short-term exercise on glucose and insulin dynamics in non-diabetic and IDD children.
- To compare the exercise-induced changes in insulin, C-peptide, and proinsulin levels between the two groups.
- To explore potential mechanisms underlying altered B-cell secretion during and after exercise.
Main Methods:
- A 20-minute bicycle ergometer exercise test followed by a 10-minute rest period.
- Measurement of glucose, immunoreactive insulin (IRI), C-peptide, and proinsulin levels before, during, and after exercise.
- Comparison of hormonal responses between 20 non-diabetic children and 11 IDD children.
Main Results:
- Non-diabetic children exhibited decreased IRI, C-peptide, and proinsulin during exercise, with significant increases post-rest, correlated with glucose changes.
- Some non-diabetic subjects showed IRI release independent of C-peptide, suggesting tissue-bound insulin release.
- IDD children displayed no significant changes in glucose or total IRI, but a fall in endogenous insulin (C-peptide) and proinsulin during exercise.
Conclusions:
- Short-term exercise acutely affects insulin secretion and dynamics differently in non-diabetic versus IDD children.
- In IDD children, exercise may lead to suppressed B-cell secretion, potentially due to hyperinsulinism and lack of glucose rise.
- The findings highlight the complex hormonal adaptations to exercise in pediatric populations with and without diabetes.
Abstract:
20 non-diabetic and 11 insulin dependent diabetic (IDD) children underwent short time (20 min) bicycle ergometer exercise followed by a 10 min rest period. Glucose, IRI, C-peptide and proinsulin were determined prior to and at the end of the exercise, and again after 10 min rest. While no significant change in mean glucose was observed during exercise in the non-diabetics, significant decreases were observed in IRI, C-peptide and proinsulin. After 10 min rest glucose as well as the three B-cell secretory products increased significantly. The change in glucose was significantly (p less than 0.001) correlated to the change in IRI. In the resting period IRI rose more than C-peptide in some subjects. IRI even rose without simultaneous rise in C-peptide indicating a release of tissue bound IRI. The group of IDD children did not show any significant changes in glucose and total IRI, while the endogenous insulin, as measured by C-peptide, did show a fall during exercise. The same was found for proinsulin. The lack of increased endogenous secretion during the rest period was most likely due to suppression of B-cell due to hyperinsulinism and lack of increased glucose concentrations during the rest period.