Pump Users - Combo/Extended Bolus At Every Meal?

I know that traditionally the Combo, Extended, whatever you want to call it, Bolus is suggested for use with high-fat, slow-digesting meals.  Up until recently, that was the only time I was using it.

In my effort to get my A1C down to "normal", I've hit a plateau in my ability to minimize post-meal peaks, so I thought I'd try using it for other foods, too.  Now I'm pretty much Combo Bolusing for every meal I eat, and alot of times I have no peak whatsoever after eating (if I'm setting all of the options correctly, that is).  Maybe this is the key to getting my A1C to a 6 or below?

Does anyone else use this option for every meal?  How does it work for you, and what are your parameters?  (Duration, ratios, etc.)  I find that the 80/20 split over 2 hours works for most meals that are low-fat.  When it's higher in fat, I do the same ratio, but extend it for 4 hours.

I only use the combo bolus when I'm eating high fat/carb meals. I also use it when I'm at the movies and I'm going to be eating over a period of time.

Really - no one else does this for most meals?  I guess I'm on an island then...   lol

hi Kim, I am a little confused.  A square (extended combo or whatever) bolus is likely to increase a post meal peaks.

The only time I find it useful, is tha high fat mixed carb meal, where a normal bolus would make me hit 40 at 1-2 hours post prandial.  for those, the extended bolus is way slower and widens and shortens that fast peak of lispro type insulins.  It kind of reminds me of how "regular" used to work.  I am glad I can program my pump to act like a shot of regular sometimes... esp when sometimes = pizza.

if I extended bolus for a regular or esp a fast carb,  I would climb to a gazillion after eating, and then slowly come back down to normal blood sugar.  Am I missing something?  sorry if I am not understanding you.

if you have high post parndials for most meals, and you aren't eating sticky rice, the best bet is to bolus a little early, say 15-20 minutes before eating.  PS this can be way dangerous, so it's a good idea to check with your doctors etc.

sorry again if I am getting you wrong.  =)


Hey Joe,

I'm not sure why it works so well for me, either, but it seems to.  I had already was bolusing 15 - 20 minutes prior to eating, and I'd still get a peak in the 180's to 200's, which is why I felt the need to start experimenting. 

When I do the extended bolus now for "normal" meals, I'm taking 80% of it at least 15 minutes before eating (like I was already doing), and then extending the remaining 20% of the dose over the next two hours.  The 80% minimizes the peak, and the 20% keeps it down, for me.


so Kim, you take your total estimated bolus, and do an 80% up front and a -20% over 2 hours and your 2 hour post prandial goes down as compared to a 100% normal bolus?     somthing is wierd, imo.    I can't see how 80% minimizes the peak compared to 100%.   

how's your basal rates, have you checked them since the summer started?  is your basal/ bolus about 50%, and how does your sensitivity compare to average insulin sensitivity (from the pumping insulin handbook)?   =)  i hope i am not grilling you - this fascinates me and I am trying to understand.

if you have delayed stomach emptying - then I can see that the 80-20 thing working but you would (probably)  be way low if you bolused 100% up front.

my other unqualified guess is that maybe you absorb insulin fast but you are a bit resistant to it, making the fast peak not efficient for your body.  there are lispro mixes that you could try which are fast start but wider and longer than plain lispro. 


Haha Joe - it's okay; I don't mind being a science experiment.  :)

To answer your first question, yes.  Weird, maybe.  Unusual, yes.  I am a very slow eater - I wonder if that has anything to do with it.  Maybe I'm a slow digester, too.

I am constantly tweaking my basal rates, but I haven't done any basal testing during the day for a while. 

Your last paragraph sounds like me, exactly.  Insulin absorbs fast (usually), but I take quite a bit, compared to what I see other people say they take.  And to answer the other question, yes, my bolus/basal is about 50/50.  I'm going to my P.A. again on Wednesday (and it's A1C time!), so I'm going to bring all of this up to her as well, and see what she thinks.  She's probably going to say "Well, if it's working, just keep doing it..."  Haha.

I should also mention - the reason I thought to try the combo bolus more often is that sometimes doing the 100% amount 15 minutes ahead would drop me to 70 or lower, and then I'd rise up to 180/200.  I figured the less up front option would help mitigate the initial low, while curbing the rise later.

Hi Kim,

I just started using the dual wave at every dinner meal per the recommendation of my APN, because I was getting high after dinner.  I am also trying to hit that 6.0 range. For the first week I did 50:50 over 3 hrs, (I guess 50:50 is a good starting point) but I still got gradually high.  And this week, she recommended a 40:60, which I didn't really understand, because I thought I would need more up front, but I guess since the high is gradual she thought I needed more later.

I feel a little weird about it, but she guareenteed that I would be using the dual wave during pregnancy, so I figured I should get it tweaked now.

I'd be happy to compare more notes!


Hi Kim,

Since I've been on the pump for the last year, I've wanted to try this, but I've been afraid of getting lows or weird high spikes in my blood sugar.  I can definitely understand the logic behind holding back some of your bolus for later for foods that that peak later.  Maybe I'll give it a try and let everyone know if my A1Cs get better!


Abbey - thanks; I'm glad to know there are two of us on the island now... haha!  I will probably take you up on that offer, too!  :)

Stephanie - part of the reason I've had the confidence to try this is that I use a CGM, so I can catch "problems" pretty early.  I also test very frequently.  That would be my precaution with trying this method - If I wasn't able to test frequently after eating, or have access to CGM data, I'm not sure I'd be as willing to do this.  If you end up trying it, let us know how it goes for you.  And good luck!  :)

[quote user="Kim"]

I should also mention - the reason I thought to try the combo bolus more often is that sometimes doing the 100% amount 15 minutes ahead would drop me to 70 or lower, and then I'd rise up to 180/200.  I figured the less up front option would help mitigate the initial low, while curbing the rise later.


=)  ok now this makes a lot more sense to me.  I am a firm believer of doing what works.  I still say don't rule out mixtures - if you need the same dual or combo bolus every time I bet the 75/25 humalog (70/30 novolog ) would work great for you.

shoot - I never checked if it was pump approved...  okay then, if it is approved for use in a pump then!    best of luck!

[quote user="Joe"]

I am a firm believer of doing what works. 


:D  Well said.  Even though I don't know why, I'm glad it "works".


Ive started doing a dual wave/extended bolus over most meals in the last 4 or so weeks and Ive found it has a great improvement on my levels. I went to a Medtronic workshop and the rep told me all meals that are 60gms of carb and over should be dual waved. I was sceptical intailly, but gave it a go.

I agree with the sentiment of doing what works best for you....but I dont think you are a loner in this one Kim!


what a great idea!! I recently started using the combo or squares for meals that aren't necessarily high fat/slow digesting but will be taking a long time to eat (multiple courses, etc). It's helped so much. It's also allowed me to enjoy a nice Starbucks treat.

The only thing you're suggesting that I'm not understanding is why you bolus so early. I would think that's contributing to your peaks, since your food isn't done digesting but your insulin is already out. There are times when I bolus after I eat to reduce peaks. Not recommended on a regular basis, but there are certain times when I've learned that it keeps my sugars more even.

Hi Suzy!  I use Humalog in my insulin pump, and while it is a fast-acting insulin, it does not work instantaneously.  I did not realize until I started using a CGM that taking insulin just at the start of the meal contributed to a very high peak in BG levels.  Scooting the bolus out 15 minutes from the meals helps me to line up the peak of the insulin with the peak of the food, so there isn't as much of a spike.   Bolusing after I eat would send me up into the 300's!  :(  Hopefully that answers your question...  ?