Question:How does insulin work, when is it needed, and how is it given?
Answer:Let's first talk about what insulin is. Insulin is a protein -- a protein that comes from an organ called the pancreas which is located in the mid-abdomen. Now, insulin has many different functions, although we usually think about insulin as controlling blood glucose levels.
Insulin is normally secreted in small amounts throughout the day in somebody without diabetes but then is secreted in much higher levels around the time of eating to control the blood glucose. In somebody with diabetes, not enough insulin is secreted from the pancreas, and in fact, in people with type 1 diabetes, no insulin is secreted, so all of the insulin has to be provided by an injection. And right now, insulin shots are the only way we can give insulin, and in fact it's been that way since the early 1920s.
Now there are really only two types of insulin, even though there are many different insulins available on the market. There is the background insulin, which mimics the pancreas' slow secretion of insulin throughout the day and overnight, and there is a mealtime insulin, or what we call prandial insulin, which patients can also inject. And so, even though insulin seems to be very complicated, in actuality it is quite simple as all we are trying to do with modern-day insulin therapy is mimic what a normal pancreas does.