Bolus Wizard/Correction Question

First, I apologize if this has been discussed before…

I’m T1 for 25 years. Pumping since 1995. Not currently on CGM. Something occurred to me yesterday while using the bolus wizard. I am typically high several hours after a meal. Yesterday went like this:

11:30a BG test = 114
11:45 dial in 0.5 correction and 12 units for lunch (Subway 6" ham on white, Sun chips and diet coke)
4:30 BG test 236 - Active insulin 4.7 Correction 4.5.

So technically I nailed the amount of insulin needed for the meal but something is way off with the timing.

Now, my question, If the pump says I have 4.7 of IOB, does that mean I have 4.7 of Full Strength IOB? I can’t see how as I took that insulin at 11:45. Wouldn’t it be more like 4.7 units remaining at 20-30% blood sugar lowering power.

Also, I have it set that my insulin hangs around for 6 hours. I’m beginning to think that may be a little long. I’m curious what others have.

Thanks for your input! Rick

Yes you still have 4.7 active units in your system at that point. You may be going high like that later because of a couple of reasons.

Maybe your I:C ratio changes, and your needing more insulin to cover the carbs your taking in. I have a couple that I use throughout the day.

Also are you giving insulin for the fats and proteins contained in the sandwich? Fats and proteins over the course of 3-5 hours convert into carbs, and hence glucose. You may try reading up on the TAG bolus, as it helps me greatly with meals like this. It states that roughly 30-40% of protein will break down into carbs, and 10% of fat will, so you have to treat them like carbs, and give an extended bolus for those carbs, but set it to around 3-4hrs post meal. Its worked wonders for me.

Thanks! I have had some good results with the Dual Wave so it may have something to do with fats and proteins. I don’t use it often because of uncertainty on how to split the bolus and how long to drag it out.


You may want to ask your CDE or Endo. Mine said start on a 50/50 split for 2 hrs and see how that works. For most common meals it works well. I use a 60/40 split on sugary meals or meals with lots of up front carbs. Both work good for their given situation. The trick is getting all that protein/fat carbs accounted for. Once I did that and had a grasp on it, my numbers post meal have peen spot on.

Try and ask your doc about it. Also like I said, the TAG group here on TuD is an excellent resource. Step by step instructions, and worksheets and all that stuff. Here are some links:…

Hopefully you can find some good info in there to start off with.

I use 4 hours for the residual insulin. It hard to estimate this one.

You may already do this (if so, feel free to disregard!), but you could try waiting for the insulin to work before eating - maybe wait 15 or 20 minutes after the bolus before eating. That way, the insulin and food will meet at a better time and hopefully you won’t go high later. When I got a CGM, I was shocked at how long it takes insulin to actually kick in. Sometimes as much as 45 mins! I have been considering going on Apidra (currently take Humalog) just to try to cut that time lag down between taking insulin and getting it to work.

I know everyone seems to think Apidra is super-fast but it takes 20 minutes for it to kick in for me. I have talked to a few other people that say the same thing and I have seen that on a couple insulin comparison charts. I do find it is a lot more consistent than Humalog was for me.

That is good to know. I haven’t looked into it much, to be honest. I do find humalog to take awhile but then again, maybe that is the best there is right now.

I agree with Soobaricsrock about learning the TAG system. What kind of insulin do you use? I use Apidra so I have a shorter duration. Here is a link to a chart that has the duration for both Humalog & Novalog at 3-5 hours so you probably do need to change the duration - that will at least help with correction boluses!

When I used Humalog, I had alot of day it just didn’t want to work. I still have some of those days with Apidra, but not as many. I do think it is a YMMV type thing & maybe it will work faster for you. The chart I just posted for Rick is one of the ones that has the onset of 20 minutes for Apidra.