Curves you use in your insulin pump - why and when?

We are pretty new users of insulin pump for our 5 years old son and have limited knowledge about the curves most users use in their insulin pump.I would request the members to let us know when and why they use these curves to better control the sugar levels.

Can you explain what you mean by "curves?"

By curves do you mean basal rates?

I'm thinking the use of the term "curves" must refer to the profile of the basal rate over the period of a day. Many of the diabetes studies that I read often use the term "area under the curve" to talk about different variables tracked over time.

Maybe the poster is from a scientific/math background.

SweetBaby, if this is what you meant, my basal profile varies from 0.4 to 1.3 units per hour with the 1.3 units/hour at 4:00-7:00 a.m. My basal rate day is segmented into 8 periods. Basal profiles are personally customized and my basal rates, as an adult, will vary a lot from a child's basal needs.

Testing basal rates to discover your child's needs is well covered by Gary Scheiner at his web site.

I use 4 hours for the "duration" of insulin, if that's what you mean. For maybe the last year or so, I've noticed that, particularly for bigger shots, my BG will go up and then drop pretty quickly at or around the 3 hour mark, when the IOB is down to a unit or two, but then tail off and stop dropping fairly nicely. It may be more practical to use 3 hours but I've always used 4 so I'm just sort of rolling with it.

curves for the release of bolus insulin depending upon the type of food you eat...square wave, dual wave, extended bolus curve etc.

Most people use Normal bolus almost exclusively but the Extended/Square can work to better match slowly digested food like pizza. The higher the fat/protein, the more the delayed boluses might work to avoid going low at first and then shooting up later.

Ah. I agree with Don, SweetBaby; normal bolus is by far most common for most foods. What IS important is to make sure your I:C are as accurate as possible. Many of us use different ratios for different meals (for example mine are 1:6, 1:10 and 1:15 for the three meals). It takes trial and error to determine these ratios. If he is generally high two hours after a meal and you are using say 1:15 as a starting point, then go down to 1:13 for that meal, if low, up to 1:17, etc.

I only use extended boluses very occasionally for high fat/high carb combination meals like pasta and pizza. For those I usually use a duration of 3 hours and spread my bolus 40/60 (40% initially than 60% spread out over the 3 hours). I also add a bit to the total amount to cover those foods. But again you will find what works for your son by trial and error. To tell you the truth I don't do it often enough to be confident in my numbers. Generally I just bolus a bit high and then correct if needed after the two hour check. (You also need to use trial and error to find your ISF - the number of points one unit of insulin lowers his blood sugar for corrections of highs. Again I have different ISF for day and night: 1:27 for day and 1:48 for night. Lots to figure out and no formula will be too accurate, just trial and error.

When I started eating low carb, I adopted a "combo bolus" for almost every meal. By combo bolus I mean an immediate bolus for the carbohydrate content of my food followed by an extended bolus to cover protein. Common protein extended boluses for me are 3.6 units over 3 hours or 4.8 units over 4 hours.

Instead of using the percentage method with a combined bolus, I actually deliver two distinct boluses, one immediate and one extended.

I determined the correct curve or bolus profile for me by trial and error. When I experimented with various curves I found bacon and eggs to be a good meal to use. It's easy to determine the nutritional content and the effort can be reproduced consistently.

The reason I use a protein bolus is due to the limited carbs I consume. My body converts a portion of the protein that I eat into glucose. I didn't used to do this when I ate higher carb.