Quick Rise Followed by Quick Drop

I have a question for the group. My son is a newly diagnosed 8 year old boy and we periodically will have a rapid rise in BG after eating followed by a rapid drop. As an example, he ate a corn dog for lunch today abs I gave him 1.5 units of Novolog. Within about 30 minutes he was at 200 so we went for a short walk. About 30 minutes later, he was under 100. This does happen periodically with or without any exercise. Can anyone offer some advice on what might cause this?

I used to bolus with my pump right as I was getting ready to eat, but more and more I’m finding I need to do it in advance. It may take some experimentation to figure out how far.
Also there is a factor called the glycemic index: two foods may have the same carb count, but one causes a slow rise that levels off, while the other causes a rapid rise followed by a drop. Your may may be able to help you navigate that.

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Hi @mm92599 yes a rise after eating is common. There are tricks to minimize it, you will learn them all.

The fast drop was because your son is likely making insulin, and because of the walk. Walking (or really any activity within 4 hours of a shot of novolog) can make it work much faster. When I know I’m going to walk after a meal I sometimes give myself much less (for me, usually only half of normal). Anyway it’s in your bag of tricks now as a way to make insulin work harder and faster, just have carbs on you in case he drops, 100 that soon after a meal can be scary. Good luck :four_leaf_clover:


Hi Mike, there was a time back in the days of dinosaurs, just kidding, when there was a test that they used to give prospective future diabetics called a glucose tolerance test. They would take a blood sample before the test to see what your beginning level was and then you would drink a huge paper cup of a super sugary citrus liquid and then you had to sit and wait for a period of time then have your blood drawn every 30 minutes (I think) to monitor how long it took for your BGL’s to go back to normal. With that in mind every ones BGL’s rise after eating depending on carbs and natural sugars contained in the food. The balancing act begins when you take a bolus of insulin and how long it takes to be absorbed and start breaking down the sugars in the veins into what the body’s cells can absorb and turn into energy. A minor change in bolus time may help to decrease the spike in BGL’s after eating giving the insulin a little head start because normal food takes longer to be absorbed by the digestive system and dispersed through out the body but injected insulin also needs time to take effect. The reason for the high maybe because the insulin’s full effectiveness was behind the food being absorbed and then catching up and with extra excercise his body burned through his reserves hence a low. Try some patience and let the insulin work before a walk which can always be done a little later if you don’t see a BGL decrease. It’s actually a balancing act but you and your son are on the right track and asking questions to achieve excellent control. Great job.

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Thank you for the great information. I typically give insulin about 15 minutes before my son starts eating but maybe we should try doing it a little bit earlier than that. I guess it’s a lot of trial and error.

We are still trying to figure out which foods affect him more than others abs I suspect your reference to the glycemic index is the key to this. Thank you for your response.

I can personally say that when my BGL after I eat goes to 250, and I haven’t bolused before I ate because maybe I was not at the house and eating out, I’ve watched my Dexcom G6 monitor after my sliding scale bolus and it takes me within 2 hours to steadily drop to within 120, 110. That may give you an idea depending on your sons sensitivity to insulin effects that an earlier boost may keep the spikes to a minimum. Having a G6 is an easy way to watch BGL’s in real time so adjusting an earlier before meal dose will help by counting down as his BGL drops. You may want to try to back up the bolus time by 10 to 15 minute intervals until you feel you’ve homed in on the best predose time. You are doing fine with your son, experimenting to fine tune his routine and it will get better. Make a journal to keep track of adjustments, times, monitor readings, dosages, results, etc. so decisions can be made by documentation. I hope this helps. Take care of each other.

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