It acts similar to a healthy pancreas in that it responds to changes in blood glucose with appropriate levels of insulin. The pancreas, however, is much more refined and capable than any man made loop will ever be. The pancreas releases insulin internally and its onset, peak, and duration are all much shorter than any insulin delivered subcutaneously. The pancreas also secretes other hormones, like glucagon, which help control glucose metabolism.
The automated insulin dosing system I use, Loop, simply modifies basal insulin delivery. It can add, subtract, or stand pat with the pump’s programmed basal rate. The incredible thing about Loop is the level of attention it pays to this process. It makes a decision every five minutes about basal insulin delivery. That’s 288 decisions every day, day in, day out. This is particularly effective overnight when I cannot and will not do that job.
When I first heard that these loop systems just adjusted basal delivery, I was skeptical that these adjustments could exert effective blood glucose control when the onset, peak, and duration of our insulin formulations are so slow. Time and again I am amazed to watch Loop ramp up basal insulin from say 1.0 units/hour to say, 3.0 units/hour, and turn a 30 minutes forecast trending higher BG line back into my target zone.
Automated dynamic basal insulin delivery is an effective tool to control blood sugar.