Our bodies require insulin to allow cells to have energy and to allow extra sugar to be stored as energy. This section will cover the important role insulin plays in diabetes management.
What is insulin?
Insulin is a hormone, which is a type of chemical messenger that allows communication between different parts of the body. Insulin is produced by the beta cells of the pancreas.
When we eat, food goes into the stomach and then to the small intestine. There, it is digested and broken down into nutrients. These nutrients are small enough to be absorbed into the bloodstream and carried to all parts of the body. When nutrients that contain glucose (sugar) enter the bloodstream, the pancreas responds by releasing insulin into the blood.
Insulin does the following:
- It opens up the cell channels so that they can take up sugar and have the energy to do their work.
- It allows extra sugar to be stored as energy for future use. The sugar can be stored in the liver as glycogen, or transformed in fat and stored in fat cells.
This animation shows how sugar is released in the body and turned into energy with the help of insulin. The animation is supplemental and repeats information from the text on this page.
What is insulin’s function?
Sugar is a very important source of energy, for two reasons:
- It can be converted quickly into energy when we need it, such as during work or sports.
- The brain and nerves rely on a constant supply of sugar to function.
Our bodies are almost always making a small amount of insulin, called the basal amount. We need this because the liver continues to release some of its stored sugar into the blood between meals and while we sleep. This way, our brain and nerves continue to get the constant supply of sugar needed to survive.
As soon as the blood sugar rises (for example, after a meal), the beta cells of the pancreas detect the higher blood sugar levels via sensors on their surface, and tell the beta cells that more insulin is needed. This lets the beta cells give out just the right amount of insulin to handle the higher blood sugar level. This burst of insulin to cover the meal is called a bolus.
When the blood sugar level comes down again, the burst of extra insulin shuts off. The beta cells keep extra insulin on hand as usual. As the insulin is used up, the beta cells produce more. The next time your child eats, the pancreas responds with just the right amount of insulin to bring the blood sugar level back into the normal range.
This system works well in people without diabetes, as blood sugar levels stay within the normal range even if they eat a lot or go without food for a long time. If a person does not eat at all, the extra insulin just does not get released.
What happens in case of diabetes?
Without enough insulin, sugar cannot be taken up and used by most of the body cells. The cells starve, even though the blood sugar concentration may be very high. As a result, the body seeks other sources of energy. This leads eventually to the breakdown of fat and the release of ketones, which are the by-products of fat breakdown.
Patients with diabetes must administer insulin from an outside source, through injections or with the use of insulin pumps, or with oral medications to stimulate natural insulin production and uptake.
This animation shows how the body responds to sugar in people with type 1 and type 2 diabetes. The animation is supplemental and repeats the information above.