Medtronic 780G meal bolus mystery

Rip

Newbie
Messages
4
Type of diabetes
Type 1
Treatment type
Pump
I have been a type 1 for 45 years and been using a Medtronic insulin pump for 12 years. My control has been excellent with A1C in the low 5s for most of this time. I updated my 770G to 780G last year. I didn't like the way the 780 won't let me increase my bolus without lying about my carb count so after several months of frustration I started running the 780G in manual mode (using a CGM sensor but not running Smart Guard). I will say that the 780G in Smart Guard does a great job in reducing the number of low BG I experienced.

At my last meeting with my diabetes health care provider the two endo doctors asked me to go back into auto mode for several months since the Guardian 4 sensor was providing better results for their patients. I agreed to try it again and report back at my next appointment late next month.

I achieved tight control for 40+ years by counting carbs, avoiding snacks, and routine exercise (walking). But my last A1C was mid 6. I blame this on the the way the 780G handles my bolus needs. The pump routinely cuts my bolus by 40-60% for breakfast which cause my blood to regularly rise to 220-260 in the next 90-120 minutes. Slightly smaller adjustments occur at lunch (0-30%) and at dinner (10-30%) but both result in my BG rising higher than I am willing to accept. I am not willing to lie about my carb count to get more insulin to slow blood glucose rise. With the current setup, my pump is delivering 10-15 autocorrections in a feeble attempt to get my BG back into target range and even with autocorrection system, I often go into lunch with a SG of 140-160.

I want to ask other 780G pump users for help in how I can stop these unwanted bolus reductions and how I can convey to my endo. doctors that the 780G in Smart Guard mode is not working well enough for me.

Just to point out a few additional factors in my treatment regime. My carb ratios work well in manual mode. I changed my active insulin duration from 3.5 hours to 2 hours when using auto mode based on recommendations from Medtronic representative. I set a temp basal rate every night just before going to bed to reduce nighttime lows and reduce alarms.
 

Nicola M

Moderator
Staff Member
Moderator
Messages
827
Type of diabetes
Type 1
Treatment type
Pump
I've never actually experienced this but I have heard stories about it in a Facebook group I'm part of, from what I can gather it boils down to the pump putting you into "safe meal bolus" which lowers your total insulin amount for safety which is great when it works in the intended way but not so great when it reduces all of your meal time boluses by a sizeable amount. There's a Facebook group I'm part of where this has been talked about a lot and a possible solution to how to get around this. You can find the post here https://www.facebook.com/groups/119376721997721/permalink/1347759939159387
 

Rip

Newbie
Messages
4
Type of diabetes
Type 1
Treatment type
Pump
Nicola,
Last week I tried to join two Facebook groups I thought might be useful, including the one you linked to. I completed the join process and answered the 3 questions. My join request was turned down because I haven't had a Facebook account long enough to become a member of this private group. No place during the joining process did I see any mention of a this length of membership requirement and my rejection notice provided no information on how long Facebook membership must be to be able to join either of the two private diabetes information groups I tried to join. It was a real disappointment to encounter this barrier when seeking information.

So I am looking for someone in this group to give me some help with this since I can't currently get to the link you provided or any other help or information on this topic on Facebook.
 

Nicola M

Moderator
Staff Member
Moderator
Messages
827
Type of diabetes
Type 1
Treatment type
Pump
The general idea is that sometimes your carb ratios can be too tight causing the pump to lower the amount of insulin it gives you. The general consensus is that you should aim for a carb ratio of equal to or above 300/TDD, e.g. My TDD is 53 so my carb ratios should be 5.6 or more. Is this a fool proof solution? Not exactly because your carb ratios may be what works best for you and changing them isn’t going to help but it’s what most people find does work for them and stops the pump from lowering the amount of insulin it gives you. I would definitely speak to your team about it as well though and see if they have any more insights or even call up Medtronic themselves.
 

Rip

Newbie
Messages
4
Type of diabetes
Type 1
Treatment type
Pump
How did you determine a TDD of 53 if you are running your pump in Smart Guard? Smart Guard is determining the doses of insulin not you. Is TDD something I can see on my 780G?
 

dancer

Well-Known Member
Messages
1,380
Type of diabetes
Type 1
Treatment type
Pump
@Rip go to History then Summary. Do a 7 day or 14 day summary and scroll down and you will find your average TDD.
 

Rip

Newbie
Messages
4
Type of diabetes
Type 1
Treatment type
Pump
Thanks Dancer. I used the 300/TDD and go a really low number that I will bringing to my Endo team's attention at my next appointment.