I’m a well controlled type 1 (5.2 A1c) but have found that the only way to avoid post meal highs is to pre-bolus by 30-45 minutes. Just as I feel my BG starting to dip, I can commence eating and return to normal BG within 2 hr post prandial. I’m normally around 85-95 pre-prandial and back to around 100 after 2 hours if things go well. I’d be interested to hear whether others need to pre-bolus this early or whether I’m an oddity. Most people seem to pre-bolus no more than 10-15 minutes which is why I’m curious.
I couldn’t go that long but it’s not a bad idea. I usually bolus no longer than 5 minutes before I eat but I check my BG in an hour after eating and usually have to give myself a correction. My problem is I’m extremely busy with clients at work and if I bolused that early and for some reason couldn’t eat, I’d be in trouble. Your 5.2 A1c is amazing. I’ve gotten down to 6 which was fantastic for me. Over the holidays my A1c was quite high and I’m working it down now… just couldn’t stay away from all the good foods and second guessed the carbs.
I have definitely found this with my son - although we rarely actually do it. He has a Dexcom, and so we can definitely see the spike. I make him wait 15 minutes at breakfast, but he still spikes (just not as badly) and at lunch - since it’s at school it just isn’t feasible to wait. Dinner doesn’t seem to be a problem, but that might be because of the food we eat at dinner? And I think later in the day he’s just more sensitive to insulin. Do you find it to be true at all meals?
Yes, I pre-bolus for all meals but need 45 mins or more for breakfast and usually 30 mins for both lunch and dinner. Without the dexcom it would be hard to judge but with CGM it’s possible to zero in on the time for onset. However, if a meal has higher protein and fat (or lower carb) I might be able to marginally shorten the pre-bolus period.
Mike, When I started the insulin pump about 20 years ago and we only had reg insulin I bolused about that much ahead of time. Now that they all have the fast insulins they trained us not to do that anymore and my sugars are a holy mess. I have actually thought about going back to the pre bolus and just start with ten mins and work my way back up. I’m soo glad you posted this b/c I’ve been putting it off and it’s a good thing to do. I’ll be following this thread to see what others have to say about it. Thanks.
Sandy
Mike, if it is that bad have you thought about symlin? From what I hear it’s great for those meal spikes.
Sandy: Thanks for the suggestion - I’ll certainly take a look at symlin, it sounds very interesting. Hope you find a pre-bolus formula that works well for you. For what it’s worth, if you have a cgm it demystifies where you stand at any given time (and the trend) and for my part it markedly reduced the stress involved in managing my insulin regimen. Best of luck to you. Mike.
My CDE says that CGMS technology has taught us that we should all be pre-bolusing that early. She says that Regular insulin should probably be bolused up to an hour earlier (we did half an hour when I was a kid) and that the ‘newer’ fast-acting insulins need 20-30min lead time.
Thanks, what you say makes sense and follows conventional wisdom and the advice I received from my CDE and endocrinologist. However, it seems like for me, it’s starting to be closer to the 45 minute mark which means a lot of pre-planning for meals - especially when eating out. In due course I hope to find a way to reduce this period (faster acting insulins? symlin?) but I’ve become adept with Novolog so either way it will mean re-education. Although my end results are good, I’m always striving to improve and thankfully I’m not alone in this quest. Mike.
Mike since you use your CGM in this process do you wait until it starts to show a down arrow then eat? Or do you wait for a certain bg # to show on the CGM?
I’ve never waited that long but I’m going to give it a try tomorrow. Since I have my CGM I will know if it starts dropping too fast. I’m looking forward to this test! 
I have finally got my A1c down to 6 but I would LOVE for it to be down in the 5’s.
Hi: Excellent question - I should have elaborated. My BG is quite stable at night (I’ve done a lot of basal testing) but starts to increase slowly just after I get up. I might wake up at 90 and be around 100 by breakfast time without bolusing. My strategy is to bolus for the full amount of my breakfast as soon as I get up. I’ll then watch my CGM carefully to look for a 5+ point reduction (not a specific number) which tells me the bolus is kicking in - this is when I proceed to eat which is generally 45 mins after the bolus. The trend to me is more important that the number itself in letting me know I’d better eat promptly to prevent a low. However, I eat more carbs at breakfast than my other meals so for me the food kicks in pretty fast and I rarely get a low. If you plan to eat a lower carb or higher protein breakfast, I’d suggest you be very careful about waiting this long to eat after your bolus. My suggestion is to eat the same breakfast every day for a week, progressively pre-bolusing by an additional 5 minutes until you find the time that keeps you from spiking (and needless to say not getting a low in the process). If you are ultimately unable to prevent the post prandial spike after pre-bolusing it tells you that (a) your insulin/carb ratio might be off (b) you need to go with a lower carb breakfast or © a square wave pre-bolus might be better. There are many other alternative options in this eventuality but these are the main ones that come to mind. Needless to say I hope the 5 minute incremental tests might yield a satisfactory pre-bolus time for you. Take it one small step at a time to prevent lows. Good luck and hope it provides the results you seek. Mike.
What you describe sounds like a dawn phenomenon. I dont usually have that so I’m definately no expert but I do know that for most people an unexplained increase in bg’s just after waking up that is the reason. But it sounds like you have a good hold on the situation.
I tried pre-bolusing by a fixed amount of time. This did not work out for me. With the same pre-bolus time I could either end up with an after-breakfast spike or with a low before I could start eating. I decided to avoid before-breakfast lows at all cost and started pre-bolusing just before I started making breakfast. This boils down to a 10-15 minute pre-bolus time. This left me with an after-breakfast spike. I then increased my bolus until the spike stayed below 120. The side effect of over-bolusing is that I go low about 1.5 hours after my breakfast. I welcome this opportunity to eat some fruit. I very much prefer over-bolusing combined with an after-meal snack compared to watching my dex for the ‘ready-to-eat’ signal.
Helmut: I fully agree with the approach - and clearly it works very well for you. My predicament is regardless of the amount of my bolus, even if I add 50%+, I’m unable to prevent the ensuing high unless I pre-bolus by a significant period. Actually the only way for me to reduce the pre-bolus period is to start the process at BG around 75. I wish the 10-15 minutes worked for me but it looks like I’m a bit unusual in the way it takes so long for onset of the insulin action. Thanks for the feedback. Mike.
Good point - I had thought of that and my basal rates (which I steadily increase from 3 a.m. based on extensive basal testing) do adjust for this effect. Thanks.
That does seem like an unusually long pre-bolus but it works. I suppose Apidra might shorten the time slightly? Have you heard of Super Bolus? It is a bolus feature that all pumps should have but don’t (shame on them). SB is “borrowing from basal and adding to bolus.” This would definitely shorten the pre-bolus time but requires a learning curve and setting a temp basal. Since you have a Dex, you would be able to figure it out and avoid lows after 2 hr post meal. Super Bolus
Thanks Don. I’ve tried Apidra but unfortunately it just did not work for me the way it has for others. I’ve also in effect tried Super Bolus’s but regardless of the amount of my bolus (and I’ve tested some insanely large numbers) I’m unable to prevent the post meal spike without the 30-45 min pre-bolus. I know it sounds illogical but I seem to be experiencing some kind of delayed onset of the insulin effect. Fortunately I’m able to keep good control with pre-bolusing, but it’s curious to me why i seem to be so idiosyncratic on this. Mike.
I double my bolus.
Wow, Dexcom must be a huge difference for you and your A1C.
Yes, if I had to pick between my omnipod and dexcom I’d definitely go with the dex. Knowing where one’s BG is at all time is invaluable and, for me, life changing.