Duration of action of insulin

[Zhnyaka]

I began to notice that my bg was greatly reduced about 4 hours after the bolus injection, but the duration of the bolus is about 3 hours, and even if the bolus acts, it should not act so much after so much time.

for example, I injected a bolus at lunch and ate, then about the standard behavior of bg after eating, but why does bg keep falling?! I was at work, no physical activity or stress, just sitting at the computer and writing code. I don't understand if it's the bolus or the basal. There is no hypo at night, so, in theory, the dosage of basal should be correct. Has anyone encountered this?

 

[himtoo]

2 possible reasons ---- 1 .... insulin duration of bolus dose can be 4 or sometimes 5 hours ...it will partly depend on what you ate , time of day etc......2.... also it could also be that basal insulin needs looking at if you are consistently getting a downward trajectory after 3 to 5 hours post bolus

 

[sgm14]

What type of insulin and where did you get the three hour duration figure from?

It seems a little too specific as most durations I have seen are given as bands. Eg Novodisk say that Novarapid last for 3-5 hours.

 

[EllieM]

Another possibility is that if you've overused an injection site that can delay the absorption of insulin (supposedly)

Factors that delay insulin absorption​

Insulin absorption can be delayed by:

• over-use of the same injection site, which causes the area under the skin to become lumpy or scarred (known as lipohypertrophy)
• insulin that is cold (for example, if insulin is injected immediately after taking it from the fridge)
• cigarette smoking.

Diabetes and insulin

It may take a while to find the right insulin dose to reduce your blood glucose to acceptable levels.

www.betterhealth.vic.gov.au

(I've got to say that the cigarette smoking and cold insulin ones are new to me but my DN has told me the insulin site one).

And I agree with the suggestions from the previous posters.

 

[Zhnyaka]

What type of insulin and where did you get the three hour duration figure from?

It seems a little too specific as most durations I have seen are given as bands. Eg Novodisk say that Novarapid last for 3-5 hours.

I use novorapid. I understand that it can take longer, but it looks like the peak of the action (as if I made another injection), which in theory should not be

 

[Zhnyaka]

Another possibility is that if you've overused an injection site that can delay the absorption of insulin (supposedly)

Factors that delay insulin absorption​

Insulin absorption can be delayed by:

• over-use of the same injection site, which causes the area under the skin to become lumpy or scarred (known as lipohypertrophy)
• insulin that is cold (for example, if insulin is injected immediately after taking it from the fridge)
• cigarette smoking.

Diabetes and insulin

It may take a while to find the right insulin dose to reduce your blood glucose to acceptable levels.

www.betterhealth.vic.gov.au

(I've got to say that the cigarette smoking and cold insulin ones are new to me but my DN has told me the insulin site one).

And I agree with the suggestions from the previous posters.

I have never smoked, in the office +20C, in places with lipohyperrophy I do not give injections...

haha, it's immediately noticeable that you live in a warm climate. Here we are taught to carry insulin in the inner pocket of a jacket closer to the body so that it does not cool down in winter or at least warm it with your hands before pricking it if it's cold outside

 

[tim2000s]

It's pretty straightforward really, and discussed in this article. The rapid acting insulins simply take a lot longer to get our of your body than you have been taught. It's all documented in their Patient Information Leaflets, where it highlights that the half-life of these insulins is around 75 mins, which means that to get to 6.25% of the injected dose takes roughly 5 hours.

 

[Deleted member 527103]

@Zhnyaka are you sure the drop is due to your bolus not your basal or even something unrelated to injected insulin such as exercise?

 

[Zhnyaka]

@Zhnyaka are you sure the drop is due to your bolus not your basal or even something unrelated to injected insulin such as exercise?

I am sure that this is not physical exercise (because I work at a computer), but I am not sure that this is not basal. It confuses me that I don't have hypo at night, but we regulate basal precisely by night bg

 

[Deleted member 527103]

I am sure that this is not physical exercise (because I work at a computer), but I am not sure that this is not basal. It confuses me that I don't have hypo at night, but we regulate basal precisely by night bg

It is not uncommon to have different basal needs at different times of the day. However, long acting insulins assume this is the case. If your basal requires a single injection per day you may find you need to split it or change to a shorter acting basal such as Levemir.

 

[Circuspony]

I'm much the same with Novorapid - it's really annoying. I find I run high during the day at work but drop to hypo levels about 5-6 pm if I've injected for lunch. If I inject more for lunch the hypos are even bigger.

It's definitely the Novorapid because I trialled a day without any carbs and although I was ravenous I didn't hypo.