Timing between BG result and unscheduled snack

[pegasus]

OK, here's a sample scenario: I do my 2-hr postmeal test. An hour later, I want an unscheduled snack. Can I use that BG result from an hour ago, or do I have to prick my poor calused fingers again? Does anyone have an approximate time frame beyond which you assume you must test before eating again?

[Subby]

You mean in regards to the bolus wizard on the minimed?

First, as far as will your blood sugar have moved from an hour ago, there is no easy answer I can give. It is up to the circumstances and your body. What do you think? Have you ever tried testing an hour apart? Do you get much variation hour to hour?

Me, my BG is always moving. I can move 6 mml/l in 20 minutes in certain circumstances. Usually involving exercise or the wrong food. Or sudden stress. But sometimes it just "Happens" for me too. Others seem to have more stability than me.

You'll need to judge for yourself as to if you think things will have changed significantly in that hour.

Remember you don't have to put any bg in if you don't want. It will go ahead with a bolus based on your carb entry. Of course, it won't add any "adjustments" for blood sugar because... well, it doesn't know. So if you feel confident you are reasonably stable, you could forgo the BG entry.

[shabbie]

hi pegasus
if i eat that soon after my meal i will just bolus for the snack without testing.
if i snack 2 hours after i will test but will allow for IOB.

do you not have an IOB calculator on your pump? (i dont so i have to calculate it manually.)

[Subby]

Sharon, can you explain the method you use to allow for IOB in that instance?

With the minimed that pegasus and I use, the bolus wizard takes IOB into account only with corrections, not with carbs. Is this effectively what you do?

By the way pegasus, to see IOB (insulin on board) you need to dial up a dose, then on the estimate details screen, scroll down for "Active Insulin". It's the same thing. I'm not sure you should worry about it at this stage, since the pump automatically takes it into account in it's calculations, if you input an errant BG level.

Man, I hope that wasn't too confusing, I feel clumsy with words today. :(

[JediSkipdogg]

In my opinion a BG result is good for 15 minutes and that's about it. Outside of that time frame you are entering into a red zone where it may have changed quite a bit. If you go past 30 minutes you enter into a black zone.

Now, that is assuming you are eating or have given insulin in the past 4 hours. If say it's been a while and you know for a fact 110% that you have nothing in your body to change the BG, then I would say a little longer time can be given.

That's my opinion based on no medical research.

[shabbie]

when i test my Bg at 2 hours i would expect it to be between 6 and 8 (108-144)
as long as i am between those 2 numbers somewhere i will only take enough bolus to cover my snack attack.

if my Bg is over the 8, i will take a correction bolus to bring me back down to say 7/126 plus the snack bolus.

if my BG is under 6/108 then i may end up going low at 3 hours so i will reduce my insulin by say 5 grams worth and then i should be nicely in range again after the next 3 hours.


sorry to go on...hope that helps ;)

edit: i just thought to add... novorapid is active for 3 hours for me..thats where i get my timings from ;)

[xMenace]

OK, here's a sample scenario: I do my 2-hr postmeal test. An hour later, I want an unscheduled snack. Can I use that BG result from an hour ago, or do I have to prick my poor calused fingers again? Does anyone have an approximate time frame beyond which you assume you must test before eating again?

I wouldn't test if my numbers and activity and 'feel' were all normal. I'd bolus and enjoy. There's a lot of repetition in our days. If your rates are decent, you have to trust that today will be like the day before and the day before and the day before ...

[pegasus]

Thanks, everyone. I'm going to print out and absorb (hopefully faster than my insulin rate--5 hours :) ), and try some of these examples.

I do know about the Active Insulin reading, Subby, and that actually leads to another question: sometimes I will test and be above my target, and the bolus wizard doesn't suggest a bolus, seemingly because the active insulin is greater than the correction needed. Does that indicate a programming problem? Do other models have similar "wizards," and do folks like them?

Should I start another thread for this :embarasse ?

[Subby]

Nope, that's the way it should work. It's saying "ok you are high, but you have insulin in your system, so let's wait and see if that insulin will bring you down, I think it will" :)

You need to run some test on this in some way, to verify your "Sensitivity" setting is accurate enough. It is in Bolus Wizrd Setup. Too high and it will undercompensate the correction bolus (or lack thereof, based on the IOB). Too low and it will overcompensate.