When do i correct?

hello, im starting to have to correct with insulin post meals. i dont know my correction factor, have only had to correct like four times in the last year. the times i have had to correct, 1 unit lowers me about 100 mg. i am two hours post meal with a bs of 202. do i correct with a unit now? or is that stacking and i should wait 4 hours until most of my meal bolus is gone?
what do you do?

You have to calculate the Bolus on Board or BOB. Let's say you took 2 units 2 hours ago for lunch. Two hours after, you would have 1 unit on board, which should bring you down to 102 within two more hour. But let's say you took 1 unit at lunch, you would correct with .5 units, as you would have .5 BOB.

This is all assumming you are on rapid acting insulin. If not, disregard all of the above....

I would definitely correct if I was 202 at two hours after lunch. However, as Spock says, you need to take into account your insulin on board. I use three hours for my duration as I use Apidra. Some people use more like 4 with the other rapid acting insulins. You say you don't know your correction factor, but that one unit lowers you 100 points...that is your correction factor or ISF. With a factor that high you need to be careful. If you have enough insulin on board, then you would not take a correction because you would still have enough IOB to bring you down. Spock is basing her numbers on a 4 hour duration; if that is true for you, then if you took 2 units you would still have 1 (1/2) left at 2 hours and would not take a correction. If you use three hours that figure would be different. So you need to determine your time of duration.

wel, it appears that the one unit that corrected me down 100 mg about 8 weeks ago now only lowers me 30 today. this is so frustrating, dont want to take any more insulin. grrr. i dont know what is going on here.

You were diagnosed, I see, one year ago, so it's quite possible that you are coming out of your honeymoon period which will change your insulin needs. There is no such thing as "too much" (or too little) insulin, only the right amount to control your numbers. The good news is having a lower ISF will make it possible to correct, say that 202, without having to just wait. Do be sure and test your ISF several times, keeping careful notations, so that you are sure it is correct; one time doesn't give you an accurate enough picture.

thank you for the advice. every time i think the honeymoon is over, it starts back up again, making complete acceptance difficult. i am now at 108 four hours after the alarm bell-hysteria 202 on the meter, so it took four hours and a correction of a unit to bring it down about 90. i thought it would come down faster in the first two hours after injecting for some reason. so this would mean that my correction factor, today anyway, was about 94. very glad i didnt opt for an angry revenge bolus an hour ago.

it is a big correction factor and i hate correcting because of it, especially in the evening.

how would i go about determining my time of duration, is it just based on the type of insulin? i use novorapid and have read that its action is about 4 hours. so then that should be my time of duration, or is it another ydmmv?

because i just corrected 2 hours post because i couldnt look at that 202!

Remember that in a perfect world your bolus insulin is needed to cover the carbs you consume and correction insulin is for correcting your BG back to your target range. Here is a link that will explain how to determine a starting correction factor.


thanks john. there is something like this is the d books i have but am just unsure because my tdd is still only 7 units at most. everything starts at 15 or 20 units. good to know about the diffs in the numbers for bolus/basal percentages, as my basal is more than 50 percent.

Duration tends to vary from person to person, but the average is about 4 hours. I use Novolog and have it set to 3.5 hours.

When I'm not on the pump (which does the calculation for me) I calculate my normal correction and cut it in half if it's less than 3 or four hours after my last bolus.