Insulin On Board (IOB)

Help! We just went in for an appointment to do a trial pump start (with saline). We are doing the first week with the Animas Ping, but then the second week with the OmniPod. Our endo office is totally discouraging us from going with the OmniPod and their biggest argument is the way it calculates insulin on board (IOB). The Pod does NOT count for insulin that was given for food, only for corrections. I'm slightly upset because it is clear that the CDE we worked with is a huge fan of the Medtronic and we are not even considering that one (sort of feels like it's sitting in the dark ages in terms of the technology and such). So she went through the Ping stuff and got us started, but really gave nothing but negative comments about the OmniPod.

My 10-year-old daughter is set on the OmniPod for the most part. I'm sure she will do fine with the Ping and that it is ideal for most people, but the Pod will still be tubeless and will do auto-injection of the site. None of the others can claim either of those benefits.

Anyway... I'm hoping someone can tell me more about the IOB issue. The CDE claims it is a safety issue because you risk dropping too low if you don't count for the IOB from food in the correction calculation.


I use the Omnipod and I'm thinking about how it calculated my IOB since I've never had any issues.  I think that if you give insulin for food, the pdm assumes you ate that food so there shouldn't be any insulin on board when you go to give another dose of insulin for your next meal/correction.  Does that make sense?

as i've learnt the ping doesn't account for IOB for food, only for corrections. so even if you go into exCARB an hour after giving yourself a dose, it won't subtract the IOB unless you also plug in a blood sugar that needs correcting.

I understand the concept that it assumes you had the right amount of insulin for the carbs you ate, but what if you mis-judged the carbs... so let's say you didn't give enough insulin for what you ate and your BG is high the next time you check. The recommended dose on the Ping would calculate the correction and then subtract any insulin you had on board so that you don't over-correct. But the OmniPod would simply give you the correction. This is how the CDE explained it to use today -- and called it a safety issue because the Pod could cause you to go low because of it.

True? or False?

oh i didn't know the Pod did that...i don't have access to it cuz i'm in canada, so i never even got to go on a trial so i donno. can't you load up the program on the remote and punch in a number as if you're doing a correction and see if it subtracts the IOB to give you a dose to take? it should break it all down for you.

but if it doesn't subtract the IOB then i can see that being a concern. i don't see why it wouldn't though..

But how would the pump know how many carbs you really ate?  When I do my insulin calculation on Omnipod, it asks me the number of carbs I am going to eat.  It calculates the carbs based on that number.  Now, how on earth would it know if I did or didn't actually consume those carbs?!?! 

You could go low regardless of how you supply your insulin by miscalculating.  I don't think you're any more likely to go low on the Omnipod than with any other pump or manual injections.

Thank you! That's what I was hoping to hear. After all, the pump can do some pretty amazing things, but it is certainly not a brain. It's like saying it knows how much exercise you plan to get in the next hour and a half and how vigorous it will be. So when my daughter tests and gets a BG of 250 and the PDM tells her to give a correction of 1 unit... if she knows she only had breakfast an hour ago, she might choose to only give a half unit or to not correct at all... isn't that how it should work? I don't think I want her to get so lazy that she always does what the PDM suggests anyway... am I on the right track?

I was on injections for 9 years (I was diagnosed as a teenager) so I got pretty used to keeping track of everything in my head.  The best part of the pump is that it does the calculations for you (so you can be more accurate with your carb counts and not round for simplicity sake) but you still need to remember what you ate/how much you've exercised/how you feel/etc.  

So yes, your daughter might decide not to correct at all.  The PDM will make a suggestion, but you can always override/ignore.  We diabetics are still the brains of this operation, despite even the greatest technology. 

I was actually told  to wait 2 hours after eating to test because that's how long, on average, it takes the carbs/sugar to be processed by the insulin. 


Speaking from our experience, we have not had any more lows since Clay started on the pod than when we were doing injections.  When it comes to testing after eating, we basically don't test until three hours after he eats, because most of the time he will be high during that three hour period.  You will also learn when and when not to correct a high number based on the anticipated activities in the next few hours.  For example, my wife checked Clay last night at 5:00 for dinner and he was something like 225.  Normally we would give him 1 unit to correct that, but he had a soccer game so we did not correct.  After the game we checked him and he was 90. 

In my opinion, you don't run any more risk with over-correcting with the pod than you do with injections.  If she were to eat breakfast, check an hour later, and then correct using injections she would be just as likely to over-correct based on her IOB.

I hope I am making some sense...LOL.  I guess I am failing to see why you would be more likely to over-correct with the pod than with any other pump.

In my opinion, it's important that your daughter feel excited about the pump she gets ... she'll be a happier user. Do you think she's at an age where she could learn to override pump suggestions that weren't right?

A big part of my concern in getting a pump at all is that Maya will become lazier about managing her disease... that she will eat whatever she wants whenever she wants and that she will let the pump think for her. So... I do have faith in her ability to override the pump's decisions, no matter which pump it is. When the CDE labeled it a "safety" issue, it scared me a little. When I pointed out that it could happen on injections too, she said, yes, but it doesn't have to be that way and had this super concerned look on her face (pointing out that it isn't that way with the other pumps). Maya is proceeding with the Ping trial right now and I plan to require her to do the OmniPod trial so she can really experience the differences. Then we will decide. My gut feeling is that we should go with the Pod -- for a variety of reasons. When I watched her getting into her PJs last night and having to hold the pump while she shimmied out of her shorts, I just thought to myself "I don't want to need to help my 10-year-old get dressed." Seriously...

I know some of the issues seem small, but to me, they are quality of life issues. And honestly, I think we can figure out the numbers and management pieces that come along with whatever approach we take. The quality of life stuff is SO important though.

Thanks so much for all the feedback! Happy to take in any more words of wisdom from experienced pumpers.

I know that getting dressed with the pump is pretty hard, and it's probably the least of your worries. The easiest way to change with the pump is to clip it to the top of your shirt when you are changing pants. If she does go with the ping, it is a great device and she is going to do great on any pump!

I am still confused about why the CDE thinks it is any more risky with the Pod than any other pump when it comes to calculating IOB, but then again, I'm not sure I have ever been accused of being real quick.

No issue is too small when it comes to choosing a pump.  It is a big decision that will affect both you and your daughter.  Good luck with your decision and let us know how things go!

The CDE says that the other pumps (the Ping and the Medtronic) will count insulin given for food in their calculation of IOB. The OmniPod only counts insulin given for corrections in calculating IOB. Does that make sense?

That does make sense.  What I don't understand though is why you would count that since it was given specifically to cover the food.  If your daughter is at all like my son, after he eats he usually will be high for a while (anywhere from 1 - 3 hours).  We don't even check him during that time, unless he says he feels low, because we know he will be high.  Our CDE basically told us not to check him until 3 hours after a food bolus in order to get an "accurate" reading.  I think there is some kind of alarm or alert on the PDM that you can set to let you know when 2 or 3 hours have passed after a food bolus.  I will play with the PDM tonight at home and let you know.

Good luck with your decision.  We were choosing between the Ping and the Pod when Clay decided he wanted a pump and I know it is a difficult decision.  From what I gather from this site, every pump (including the pod) has some kind of issue from time to time.  We have had a few issues with Clay's since he started on it back in July, but all-in-all we are extremely happy with it.

Thanks so much. Your comments are so incredibly helpful as we are researching these and trying them out. I feel like this is such an important decision and want to make sure we do everything possible to get it right. Like I asked the CDE yesterday though, "Pretty much everyone is happy with their pump once they get it and have used it for a while, right?" She didn't want to agree with me on that, but most of the posts here lead me to believe there are very few people who are unhappy with their pump (especially in comparison to injections).

Thanks for taking the time to share your experiences! One more thing... we've heard the size will decrease by 40% in the next 6 months. True? Or just an empty promise?

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oh i didn't know the Pod did that...i don't have access to it cuz i'm in canada, so i never even got to go on a trial so i donno. can't you load up the program on the remote and punch in a number as if you're doing a correction and see if it subtracts the IOB to give you a dose to take? it should break it all down for you.

but if it doesn't subtract the IOB then i can see that being a concern. i don't see why it wouldn't though..


Minimed does this as well but you have to check your blood sugar or put in a fake one to find out how much Insulin is still in your system.


I have never really thought about it that way, but you are probably right.  Most people do seem to be pretty happy with their pumps (especially compared to injections).

We also heard that the size will be decreasing by 40% soon.  I hope it's true.  The current size is not bad, but it would be nice if it were smaller.  We were also told that around the same time they are coming out with a compatible CGM.  We are not quite ready for that yet, but it would be nice to have that option in the future.

The Omnipod's size is decreasing by 40%?  Where did you hear that!?!?  That would be fantastic!

Our Endo, CDE, and Insulet Rep all told us that.  But, we have not heard a firm date on when it will be out.  Maybe someone else on here knows.  We would love to know when it is coming out in the smaller size.