The mechanisms involved in the release of insulin are quite complicated:
- Glucose in the bloodstream moves into the beta cells
- During a series of processes in respiration (glycolysis, Krebs cycle, ETC) this increases the production of ATP
- Increased ATP causes the KATP channel to close
- K+ (potassium ions) build up inside the cell. This causes depolarisation - more positive ions inside than usual.
- Depolarisation causes Ca2+ channels to open
- Ca2+ (calcium ions) enter cell
- Initiates exocytosis where vesicles (small balls) containing insulin bind with the cell surface membrane and insulin is released.
The key thing here is that insulin should only be released if glucose is entering the cell (step 1). There are a number of reasons why insulin might be released when glucose has not entered. Some of those are unknown and others can be explained by genetics. The reason for the insulin release will determine the medication that works for the child.