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Pre bolus timing

Jessitalia

Jessitalia

Well-Known Member
Hello all, I had a slight anti- eureka moment and wondered your thoughts on it. So I was on Novoraoid for years, since 2006 or something, and I SWEAR they told me that I could inject once my plate was in front of me. So that’s what I did.

Then this year my new diabetiologist said I should’ve been injecting 15 mins before I eat, which makes sense. So l’ve beeb trying to do that to curb post meal rises.

Anyway. A few days ago before bed I felt a slight low twinge, did a test and had perfect blood sugars (5.6). But 20 minutes later I was hypo (3.2)! I’d not eaten for a few hours or exercised.

So my question is, how are you meant to blood test and carb ratio 15 mins before a meal when your BG really could change in those 15 minutes? Is there an answer to this?
 
Hi @Jessitalia

Pre bolusing in a perfect world does work well as the peak of your novorapid is timed with the spike in your carbs. So when your BG levels are holding steady.

However if you are in free fall with your BG levels or have miscalculated the carbs eaten or eaten high fat content with your food then this doesn’t work.

Folk who use a cgm like the libre can manage this far easier as you can view the direction your BG levels are going along with the information of what the impact of this timing will look like.
 
The only way to really pre bolus successfully without risking a hypo in my opinion is a Libre or CGM, I myself need more than 15 minutes for breakfast, 10 minutes for dinner and only 5 minutes for tea, it also depends on where you are injecting as each area has a different absorption rate, also to take into account is what the meal consists of so if its a lot of fat then splitting it might be the best idea xx
 
I find pre bolus successful 95% of the time.....and thats likely down to basal and ratios being fine tuned.....

If they aren't right, it wont be as successful...

Are your doses adjusted within an inch of their life...? :)
 
Thanks guys. It was the Libre that caused him to recommend this 15 minute thing! Tbh I think as I do my own research I realise I’ve been so focussed over the years about carb counting that I’m only just beginning to understand the more subtle things that medics forget to mention (time of day, injection placement). This is after 29 years!!
 
Jessitalia said:
Thanks guys. It was the Libre that caused him to recommend this 15 minute thing! Tbh I think as I do my own research I realise I’ve been so focussed over the years about carb counting that I’m only just beginning to understand the more subtle things that medics forget to mention (time of day, injection placement). This is after 29 years!!
Click to expand...

Fortunately these things are all covered in DAFNE or other local variants...;)
 
I take Novorapid and I take it just before I am going to eat. It takes about 20 minutes for the Novorapid to kick in fully but it also takes some time for what you have just swallowed to get into the blood stream. In addition to carbs, it's important to consider what you are eating the carbs with, because the ratio of fat and protein to carbs affects the absorption time of the carbs.
 
Juicyj said:
Hi @Jessitalia

Pre bolusing in a perfect world does work well as the peak of your novorapid is timed with the spike in your carbs. So when your BG levels are holding steady.

However if you are in free fall with your BG levels or have miscalculated the carbs eaten or eaten high fat content with your food then this doesn’t work.

Folk who use a cgm like the libre can manage this far easier as you can view the direction your BG levels are going along with the information of what the impact of this timing will look like.
Click to expand...
I have found those arrows highly suspect. I’ve had readings of, say 5.5 with arrow pointing North East and minutes later showing 4.0 with arrow pointing South ie an impending hypo. The only arrows I give consideration are those pointing North or South - the rest are pretty random!
 
novorapidboi26 said:
Probably forgotten, which is OK....

Do you still have access to the DAFNE Handbook.....?
Click to expand...
No, it was over 10 years ago now. I’ve had subsequent dietitian appointments though and they’ve never mentioned it. It’s the injection site thing that really blows my mind though. All I remember being told is don’t inject in a place you’re about to exercise with and move them round.
 
Hi I have the same issues with my bolus injections.... I carb count and use the Libre but recently struggled with my breakfast especially some days it can take 1hr for the insulin to kick in hence I get a higher reading than I’d like.
Consequently of an evening totally the opposite bolus kicks in within 30 mins catching me out and end up with lows....it’s a tricky balance but I’m finally understanding the carb/insulin ratios using the Libre. I try now to delay my bolus of an evening until I see the arrow pointing NE and it does work.
I understand that Novo have an even quicker insulin than Novorapid which does take around 15 mins not tried it but very interested.
 
TonyBlue said:
Hi I have the same issues with my bolus injections.... I carb count and use the Libre but recently struggled with my breakfast especially some days it can take 1hr for the insulin to kick in hence I get a higher reading than I’d like.
Consequently of an evening totally the opposite bolus kicks in within 30 mins catching me out and end up with lows....it’s a tricky balance but I’m finally understanding the carb/insulin ratios using the Libre. I try now to delay my bolus of an evening until I see the arrow pointing NE and it does work.
I understand that Novo have an even quicker insulin than Novorapid which does take around 15 mins not tried it but very interested.
Click to expand...
https://tcoyd.org/2018/04/the-newest-fast-acting-insulins-how-fast-is-fast/
 
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