Duration of Insulin Action Time vs. Insulin Action Time

I am currently reading Pumping Insulin and I just started pumping with the T:Slim this week. During my training I was instructed to set my Duration of Insulin Action Time to 3 hours. But according to the book Pumping Insulin this is not correct. In the book it states that Duration of Insulin Action Time is not the same as Insulin Action Time. The book recommends something closer to 5 hours. I have more confidence in this book so I changed my setting to 5 hours. So now my IOB will count down from 5 hours after a bolus.

Has anyone come across this?

I have mine set to 4 (MM Pump), but during pregnancy we decreased it as my insulin needs rose.

I'm on Humalog and my time was set to 3 hours initially. However, my diabetes nurse recently changed it to 4 for the reasons you've mentioned. Just confirming that it's not unheard of.

I use a medtronic pump & my diabetes educator said 4 hours for action time is correct.

Mine is set at 4 hours also.

We like to say “your mileage may vary” (YMMV) and that certainly is true here. I believe Pumping Insulin provides you a series of steps for figuring out what your insulin action time is. Mine worked out to be 3.5 hours, some one else’s might be 3 or 4 hours, but the real trick for you is to sort out what your time is.
Good luck and cheers, Mike

How did you figure out what your time was?

One touch ping, our soon to be 8 year old daughters is set for 3.5 hours. (humalog)

*Lightbulb* gald I found this thread....bew to pumpiing and now explains when I am doing alot of correction bolus at times followed by the big crash and staying in the 50s for a good while. I too am on Humalog and will try changing it from 3 to 4 and seee if the stacking effect will go down!

I started at 5 hours and went down to 4.

Interesting. (3+4)/2 = 3.5

That's where mine's set, and it works perfectly for me

This is a parameter that will vary some from person to person. It is affected by how fast your liver metabolizes insulin, and this is not a strict, fixed response.

Where it gets a little bit critical is when I'm eating something and BG is already below 115. Maybe just a little, maybe significantly. Anyway, at least with a Minimed pump, it deducts "Active insulin" from the bolus when you're high, but not when you're low, which strikes me a rather dangerous. I deduct it manually before telling it to start the bolus. I realize (as people have said) that the number isn't by any means exact and can vary anyway, but crashing ain't fun so I'd rather err on the "safe" side.

I have my accu-chek set for 4 hours with offset of 1 hour

Always used four. Curious as to the formula he might suggest in the book. Now I have to go look it up!!!!

Essentially you take a correction dose when you are high BUT have no other rapid of food working on board. You test over time to see when your BG finally levels out. The time it takes for your numbers to remain the same is your DIA. For me on novolog it has worked out to 3 hour 45 minutes.
Its important to test it ocassionally so you don't stack insulin by correcting too often but also don't delay a correction because you think you still have insulin action when you really don't.

I think it might be really tricky for me. Under most circumstances, I can get a 200 point drop out of one unit in one hour. It's really making it difficult to get good test results. Very insulin sensitive.

Have you tried half unit dosing via pen, or insulin syringes that let you estimate quarter units?

That kind of sensitivity is a reason to pump if you can get one, and if not have you thought of using diluted insulin?

I uses U50 novolog. Th manufacturer makes a diligent for novolog. Your endo can get it for you. It is commonly used in children who do not need large doses.

This is my 14'th yr on a pump! I just have the sensitivity setting set really high...one unit to 150 point drop.

wow! That’s really insulin sensitive.

And if it’s really late at night, I can get a 200 point drop from one unit (though it is probably clashing with my overnight downward trend.)