670G makes me low - HELP

Hi. I’ve been a type 1 for 34 years and a pump user for 20. As of about five years ago, my doctor refers to me as a brittle diabetic because from one day to the next, I have dramatically different insulin needs. After 2 seizures in 6 years -the second of which landed me in the ICU for a week with a TBI - with no forewarning low sugar or bolus on board, I was really excited about the Minimed 670g.

Here’s the problem. When Auto Mode works, I can have a beautiful day hovering around 130. Even when I have a ‘running way high’ day, it still does better than I could with my 630 and pre-programmed settings. The problem is that it won’t let me set my target higher than 120 (yeah, I know about the 150 temp) and it’s constantly overshooting. When you only take about 0.5/hr in pre-programmed basal, it’s hard to turn around a falling sugar.

Anyone know any way to completely override the system and change my target to a higher number? Like 175? If I’m aiming for that higher number, maybe the pump can’t overshoot to 40 again.

Thanks for any advice (and any computer programmers that have figured this sh*t out).

I have had the same issue. The only work-around I have found is to suspend for an hour or more. My basal is 0.45/hr and I have suspended several hours without going high. I know that is a big no-no, but I couldn’t find another way. One problem with doing this though is that if I suspend for a few hours, sometimes it kicks me out of automode bc it is calculating the active insulin. This can take an hour or more so I have started suspending for an hour, the resuming for 20 min or so, the suspending again. Not ideal, but it has worked for me!

Hi Dani,
Your reply made me think of an idea. I’m going to see if setting my “High Alert” to what would really be a desirable target for low will give me an alert when my sugar is falling to that number. If it does, then I can suspend before the pump does it on its own. Will let you know if this weird work-around works.

You should have low and falling alerts as well as high alerts…

Yes, I do. It won’t let me set the low alert higher than 90 though. Based on my experience to date, “Alert before low” and “Alert on low” targets for 90 come too late for the pump to correct on its own.

What do you have your Active Insulin Time set at? That’s the most powerful adjustment they’ve left available to the user. Again, there are set limits–my problem was running too high, so I had AIT set to the minimum of 2hrs, and wished I could have taken it down further. But you might try increasing it if you haven’t already. IIRC the max is 4 hrs.

As a side note, I think it’s important to recognize that almost everyone ends up with an AIT setting different from what they had on their manual pump. You almost want to think of it as just a knob you can turn to increase or decrease how aggressive the pump is, rather than some scientifically objective measure of how long insulin remains effective in your particular system.