Pump and blood sugar idiosyncracies

Hi. I currently use the Omnipod with Humalog insulin. Prior to that I used the Medtronic pump. I switched it out because we have a pool and I prefer not being attached to something that can’t go in the water. I have been pumping since 1997. I don’t recall noticing this in those early years, but I was also using Novolog insulin until my insurance company decided they knew better than my dr.

My normal routine consists of check BS then bolus for the food I plan to eat. About 15 minutes after I bolus, but before I eat anything, my CGM will tell me that my BS jumped between 50 - 90 points. If I test my blood, it will confirm the CGM reading. Has anyone else experienced this? If so, what type insulin do you use? Have you gotten any answers on why it happens?

Anything you can tell me is greatly appreciated.

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Morning yes.

Mostly any other time of the day - no.

We use Humalog and have not noticed this behavior, on the other hand, we usually prebolus by 45 minutes, not 15. So the insulin has time to work in my son.

God how i hate those pesky know-it-all insurance companies!!

i know that they are supposed to be the same/similar, but perhaps Humulog just isnt for you. did you have this same problem when you were using the NovoLog?

i used to use Humolog and switched over to NovoLog but didnt have any substantial reaction.

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Yeah - the infamous “dawn phenomena”. but this happens whenever I bolus, not just the mornings. Thanks for thinking about it.

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Thanks. The 15 minutes is when I noticed the jump in blood sugar, not the amount of time I allow before I eat. Humalog works so crappily with me that I take the bolus an hour to an hour and a half before I eat. I try very hard to not allow my BG to go above 100. I could keep things in much better shape with Novolog, it is much more difficult with timing differences I see with Humalog. This is a typical meal time - I check BG and it is at 88. I know that the dinner I am fixing will provide 70 carbs so I bolus for that. 15 - 20 mins later my BG is about 150 with NO food. I then wait an hour or so until it is back down to what I bolused on before I eat. Doing this I often drop low while eating. Makes me want to rip my hair out!! I do appreciate your input.

I wasn’t monitoring as closely on Novolog because I didn’t notice any issues. That, however, would make me suspect that I didn’t have this problem. I do know my timing on things with Novolog is vastly different than it is with Humalog. I know Humalog isn’t for me. However, even with a drs request, my cost goes from $600 every 3 months to $900 and we can’t afford that.

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Do you have a CGM? If so, you may want to save a few of the tracks and show your physician so they can help you appeal the Humalog/Novalog choice of your insurance company. Some things are worth fighting for.

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I did fight it and we got the ok, but what they claim is the difference in cost that I have to cover is not affordable for us. I can function with Humalog, it’s just more of a struggle. But when I remember what things were like when I was first diagnosed 45 years ago, I can suck it up and struggle.

I understand, and that is definitely not ideal. If you would like to test your theory about Novalog, you can always purchase a couple of vials from Canada for about $100 and show the difference, or figure out that it is you and not the insulin. Might be worth the effort.

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@tonimp is it possible that your basal rate is too low and that your BG is going up because of that? If it’s rising right after you bolus I don’t think that it would be the bolus that is not working.

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i’m on Medicare and am in what is refered to as “the dounut hole.” that happens when you max out your allotted amount of insurance by the carrier, and you are left having to hold the bag until the next “cycle” comes around (every January 1st) so i went into the hole at about 1/2 way through the year. with 6 months to go on my own dime. i used to pay $40 for 2 vials of Novolog, now i pay $200 per month. (and i get “Extra Care” from CVS which helps pay for some of the cost.) ( and i have other illnesses which require very costly medications as well; i dont know how people deal with this unless they are on their state’s Medicaid program; which is, believe it or not, the “Golden Ticket” as far as all perscriptions go; they pay 100% all of the time for everything!) so basically, at least in NYS, you can be too poor to live but have all of your perscriptions for free, or just a hair wealthier and too poor to pay for your perscriptions. sheer insanity.

i am so sorry to hear of your dilemma. i know how incredibly frustrating it is. (and we just, coincidently, returned from the pharmacy.)

my prayers are with you and your family. at the very least, know that you are not alone.

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have you thought of returning to the archaic R insulin? if you must wait so long with a pre-bolus, you might benefit from R. obviously the Humolog isnt working for you. does your endo have any ideas as to why this crazy thing is happening???

i have one more question for you: are you using the Humolog in your pump as well for your basal rates? or have you returned to MDI?

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Humalog is also what is used for my basal rates. What makes you ask? Also, I’ve talked to my endo and he has no idea why this is happening. I have the same problem with R - it takes it 2.5 to 3 hours to start working and then it hangs on for 8 to 10. Back in the day when I was using regular and lente I’m not sure there was a choice between Lilly and Novo. That was a long time ago! The animal based Regular I was allergic to and even the humulin would cause a slight reaction when I was able to go in that direction.

Currently, over the last year my A1Cs are between 5.8 and 6.4, so I really can’t complain. I’m looking in to Novolog from Canada and we’ll see if that flies. Thanks for your wonderful questions! They have really made me think.


@Lisa Hi Lisa,
I don’t think my basal rate is to low. If anything, it is too high. If I check it by not bolusing and not eating I spend the day between 70 and 80. My study drs (I was in the DCCT study and am now in the EDIC study) all shriek when they look at my basals. I’m going to look for a new endo as I don’t trust this one. I have time to find one now, I didn’t previously.


the reason i am asking is that if you are getting the Humulog from your pump for your basal rates, i was wondering if you were experiencing the same problem, or if it only occurs when you bolus for meals.

i wear a MM pump and only use Novolog for both basal and bolus.

I wonder if the omnipod delivers the bolus faster, causing pooling of insulin and slower absorption.

I have been switched Humalog and Novolog a few times by insurance. Novolog has been slightly faster, but not much.

Maybe try 2 bolus doses a few minutes apart, or one with syringe to see if it makes a difference.

I use minimed pump, so not sure how omnipod delivers bolus.


@daisymae I only notice it when I bolus for meals. My graph line has never flatlined. It always has minor dips and hills, just not huge amounts. It might show running at 85 then 87 then 85 then 83, etc. I was told that can be due to machine error. I’m going to run some tests on my own.

@MM2 Interesting question. I would say that the Omnipod delivery is slower than I used to get it from my MM. Once again, I’ll have to do some checking on my own. Trying 2 boluses a few minutes apart is a great suggestion. I do know that if I use a syringe it does the same thing.

i find this absolutely baffling!!! how can Humolg have such dramatic differences in its absorbtion and delivery to you? have you asked your endo or cde? this sounds insane. i know you pre-bolus, so it cant be that, IMHO. but i am stumped. havent a clue how to advise or help you.

This idea could also be applied on different days - like test with a syringe and then on another meal/day try the pump - all insulin from same vial if possible.

ETA: Doh! You already said that!

Is the drop happening on the same day you install the pump/infusion set (like, is day 1 and day 3 vastly different in absorption rate?)