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Discussion Starter · #1 ·
I still would like to know about "insulin on board". If you are taking rapid acting insulin and you have covered your carbs precisely, how can you still have insulin that is active for up to 4 hours? I don't understand this. :noidea:
 

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I still would like to know about "insulin on board". If you are taking rapid acting insulin and you have covered your carbs precisely, how can you still have insulin that is active for up to 4 hours? I don't understand this. :noidea:
This communication stuff isn't easy, but I think you are wondering about the time? If your carbs are in the bloodstream in 1.5 to 2 hours and the insulin takes 4 hours to act, how does that work?

The carbs are faster and that is really good. If you have a meal with only carbs, you get a surge of them quickly. The insulin works a little more slowly at taking down the hill (on the bell curve). That's how the time thing works.

Protein take about 4 hours to digest, so it is good that the insulins last this long.

With a carb meal it takes awhile for the insulin to catch up, and your glucose is above normal for the first part of that 4 hours.

Dr Richard K Bernstein "The Diabetes Solution" recommends eating mainly protein for this reason, and using R instead or rapid acting insulins. You would have to read the book for the details.

It's the only book on diabetes that I ever recommend. I don't follow it completely, but it is important to understand the way he uses insulin. Using his basic techniques, I have never had a 3 month average above the normal range.

That's as the normal docs define it. He gives a much more narrow normal range, and I haven't managed to stay in that for my 3 month averages.

best wishes
lia
 

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Discussion Starter · #3 ·
I should have been more specific about my question. If I take Novolog at mealtime and cover my carbs with insulin and then in 2 hours I want to have a snack with carbs. Most will say not to take more insulin because you still have insulin on board. How do we still have active insulin on board if we have used that insulin to cover the mealtime carbs? If I don't cover my carbs with insulin everytime that I eat, then I will end up with a high reading.
 

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I haven't used Novolog, so don't even know how long it is active, but I think it is one of the fast ones, 4 hours?

I'll give an example with Humalog, which works well for me. It acts over about 4 hours.

If you think of the blood sugars and the insulin as bell curves on a graph, the curve from the sugars entering the blood will be high and short if it is a carb meal. They will be in the blood in about 1 and a half hours.

The Humalog entering the blood will be a lower, longer curve, about 4 hours. At the end of 4 hours, if the insulin has matched the meal, your bg will be back to normal.

Also, if the insulin has matched the meal, the area under the 2 bell curves will be the same.

If you are using a slow insulin, the sugars from the meal won't be covered until the insulin has finished acting. Your bg levels will be higher until then. The insulin does not just sit in a reservoir and jump out when sugars appear.

If I have eaten one meal and injected enough to cover it, and then have another meal 2 hours later, I will just inject again, enough to cover that one too. It will be 4 hours after the second injection before everything is balanced out.

This communication stuff isn't easy, and to me that's normal. It often takes a bit of back and forth to get at the key to a problem. If things aren't clear this is one of those areas where it is worth the effort to get them clear.

best wishes,
lia
 

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Discussion Starter · #5 ·
Ok-then why are we advised not to stack insulin doses? Say I eat my meal and cover my carbs and this would mean that that injection is all used up. In 2 hours, I eat a snack with carbs and inject more insulin and this injection will cover the carbs for the snack. Many experts say that this type of "stacking" doses will often result in a low blood sugar reaction. I am not new to using insulin, but I have this question about still having insulin on board and no one can explain how this can be true. I guess there are some questions that can't be answered. I have asked an expert on another diabetes forum the same question and got no reply. I have asked 2 diabetes educators, my pharmacist and my PCP and a rep from Novo Nordisk and no answers. I guess I will continue to cover my carbs whenever I eat and hope that I don't go low after all is settled.
 

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I would think you could call a nurse at your Endocrinologist office and clarify this question.

Do you have a free snack limit? For example...if you eat less than 10 carbs, you don't need to cover this with Novolog? I would think you are doing the right thing to cover carbs other than the occational free snack if you are counting carbs and dosing with Novolog...that is what I do, too.

tammy
 

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Breeze, Novolog and Humalog take 4 hours to work their way out of your syste, If you inject or pump 6 units of Novolog at mealtime, that 6 units will take 4 hours to be be used up. About one quarter of the insulin is used each of the 4 hours. If you initially bolused 6 units, and you have a snack two hours later, then only half of the initial dose has been used, and the other half is still in your body (3 units still on board). If your snack requires 3.5 units (using carb counting and your carb ratio) then you would subtract the 3 carbs still on board from the 3.5 needed for the snack and bolus only 0.5 units. That is easy to do with a pump, I can even bolus 0.1 units. A half unit can be done with a syringe if tou have a syringe that has half unit markings, otherwise you do the best you can with other syringes.

If you had that snack 3 hours after the initial bolus then there would be one quarter of the initial bolus (one quarter of 6 is 1.5 units). You would subtract 1.5 from the 3.5 units needed and bolus 2 units. Taking the IOB into account avoids stacking, and hypos are not likely to occur.

Has old man Richard explained things OK, or do you have more questions? Lol!
 
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Discussion Starter · #8 ·
Breeze, Novolog and Humalog take 4 hours to work their way out of your syste, If you inject or pump 6 units of Novolog at mealtime, that 6 units will take 4 hours to be be used up. About one quarter of the insulin is used each of the 4 hours. If you initially bolused 6 units, and you have a snack two hours later, then only half of the initial dose has been used, and the other half is still in your body (3 units still on board). If your snack requires 3.5 units (using carb counting and your carb ratio) then you would subtract the 3 carbs still on board from the 3.5 needed for the snack and bolus only 0.5 units. That is easy to do with a pump, I can even bolus 0.1 units. A half unit can be done with a syringe if tou have a syringe that has half unit markings, otherwise you do the best you can with other syringes.

If you had that snack 3 hours after the initial bolus then there would be one quarter of the initial bolus (one quarter of 6 is 1.5 units). You would subtract 1.5 from the 3.5 units needed and bolus 2 units. Taking the IOB into account avoids stacking, and hypos are not likely to occur.

Has old man Richard explained things OK, or do you have more questions? Lol!
I will make this my last attempt...If I need 5 units of insulin to cover my carbs, how can I still have any active insulin left? I know it stays in your body for 4 hours.
 

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Breeze, I sent you a PM.
 
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