Meal Bolus Timing, Tight Control, and Lows -- A Multipart Question


#1

This is sort of a question for all T1’s, but pumpers in particular: I’ve had great success by “pre-bolusing” for my meals (bolusing 20 - 30 minutes prior to eating), but as my control is getting tighter with my averages approaching and dropping below 100, I’m fearful of dropping low quickly after the bolus and then compulsively over eating to compensate for the pre-meal hypo, resulting in post-meal highs (it happened last night).

I hope that this description isn’t too convoluted…

So the question is this: If you “pre-bolus”, do you take into account a borderline low pre-meal BG? If so, how do you manage it? What success have you had in not over eating with pre-meal hypos?

Sorry for the convoluted question, I hope what I’m asking makes sense. I’ve found that issue is very confusing to non-diabetics :slight_smile:


#2

Great topic. I’m not pumping, but I have noticed recently that I need to inject immediately before eating to avoid going low while I wait the 20 minutes. I am usually low to mid nineties before meals. My numbers are running quite a bit lower and that seems to make a difference in when I need to inject.


#3

Thanks for the reply! I’m usually solid with the early bolus, it just that insatiable urge when I’m right on the edge of being low. I don’t want not bolus correctly and go high postprandial, but I also don’t want to go low right before a meal and then go to town on the bread basket either!

Oh, the good times of diabetes!


#4

I have heard that if you are below 100 before a meal, you should not pre-bolus but bolus as you begin eating. Also perhaps by pre-bolousing your insulin and going high later, the insulin did not last long enough after your food had fully digested since you injected that early, but the high was probably caused by over eating and not bolusing enough for the extra food??, since you felt sooo low.

If you are having a hypo pre-meal, you need to eat your carbs first, to stop the urge to overeat quickly. It is amazing how little you have to eat to get you out of a low, but your feeling of the hypo is what causes us to overeat. If you do over compensate and eat, you still have to bolus for the extra food, which I am sure you know


#5

If I’m at 100 or less I don’t go more than 5 minutes before eating on a pre-bolus. I change that to 10 to 15 minutes if I’m up to about 125. Over that up to 20 minutes. I usually forget, though, and bolus after I’ve started eating. Doh!


#6

I’m the same way. If I’m running at a high blood sugar before the meal, I’ll bolus and wait, but if I’m 100 or lower, I’ll eat immediately. So far that has usually kept me from going low.


#7

I prebolus - 20-40 minutes (depending what i am eating)—if i am over 80 - under 80 i shorten the prebolus to 10-15 minutes(and sometimes regreet it. i pre bolus - for the same reasons you want to…to keep from going to 250 post meal - if i am under 80, i eat 2 glucose tabs and still pre bolus…

I recently started treating all my lows with glucose tabs --B-O-R-I-N-G-- But Glucose tabs work quickly and becuase they are so boring-- they are hard to over eat. You may need 3 or more to bring you up…that is somethign you have to figure out for yourself… Even if i start a meal low, and dont pre-bolus…i always sky rocket after…


#8

I repeat everything Mollie just wrote.

The lower my BG, the shorter the gap between my bolus and food - but I generally bolus 15-20 minutes before a meal. If I haven’t pre-bolused and my bgs are normal, I try to save the carbs to the end of the meal. If the meal is delayed and I’m afraid of a low, a few croutons or nibbling on some carbs won’t hurt. (Unless you get your hand slapped for picking at the food.)

Glucose tablets are boring, but I know exactly how much carbs I’m getting and exactly how much my bg should go up when I take one (4g carbs=10 pts BG - your mileage may vary).


#9

Well with my pump I can not even bolus if I am at or below 75. So I really dont know


#10

As many have said before me, great topic. This is definitely a tricky one. I’ve generally had great luck with pre-bolusing 20-30 min before meals (more if I’m on the high side), but like you I have run into some issues with borderline low BGs - I tend to panic eat when I get low and often overtreat as a result. Depending on what I’m about to eat and how quickly I think it will kick in, I may do a square or dual-wave bolus to ensure that I get the right amount of insulin while giving my BG a little time to rise. If I’m having something that makes me rise pretty quickly, I’ll usually bolus as I start eating. If I do eat more than intended I lace in a little extra insulin to cover it.

Emily, are you on a MM pump? If so, you should still be able to bolus even if below their limit, but it will take a certain number of carbs to “tip” the bolus above 0. This ends up being a handy feature for figuring out exactly how many carbs it will take to bring you up :slight_smile:


#11

For breakfast I generally pre-bolus about 60 - 75 minutes before eating my actual meal. I have a cup of coffee during that time, and I’ve watched my BG (on CGMS) trend up and then not start back down until over an hour after bolusing. I want to start eating just as my BG has started down (assuming a 100ish level).

For other meals the pre-bolus is 20 - 30 minutes early.

Before I got on the pump or the CGMS, I was operating on the false assumption that the humalog would act so fast, I shouldn’t take it until I’m about to take my first bite of food (my GP told me I might even wait until after I eat, if I’m at a restaurant). I now know that advice was bad and I can get a much better timing match of BG and insulin activity when I pre-bolus.


#12

Ken, I thought the same thing when I was on shots! If I were scheduled to eat at 12:00, I wouldn’t take my Humalog until 11:59, because I was told it’s very fast. That’s why this question of “pre-bolus” kinda threw me. I was like, why are they bolusing 20 -30 minutes before eating?

I have saline in my pump now, but go live next week - thanks for your feedback to Tim’s question - you’re helping me too!


#13

If you’re just starting out, take it easy and slow. Your absorption rate could be faster than mine. It wasn’t until I got a CGMS that I was really able to safely push the limit (so to speak). But if you’re willing to test frequently enough, you can figure out the same thing for yourself without a CGMS.