Diabetes360 App in conjunction with Dexcom G6

Hi everyone

I’ve been using Dexcom G6 in conjunction with the Diabetes 360 App, the CGM is great. I’m 53, I’ve had Type 1 for 40 years and I use a pen for injections, have been using Dexcom since November 18.

However, I’m finding it difficult to understand what’s happening with the IOB calculations, and I’m hoping that someone might be able to explain. I understand that the insulin I inject is logged when I press save and then I can see how the amount of insulin I have on board counts down over time using the % of what is left values as set in the IOB settings eg after 1 hour, residual is 75% and after 4 hours residual is 0% etc.

Here are examples of what I don’t get:

  • I log on the app that my blood glucose at 171, and I’m going to eat CHOs at 44g. Diabetes 360 recommends injection of 4 units. I save this, inject and eat the meal. Immediately after the meal I want to eat extra, say an apple at 20g cho. I log my blood glucose which hasn’t changed much and add 20g cho, but the App says 0 insulin? Why not more insulin if I’m eating more carbs? Have IOB for meal, surely now need more insulin for additional carbs?
  • In the situation above, when I decide to override the suggestion of 0 injection, and add injection of 2 units for the apple, why does the app cross out the IOB above (ie the residual of the 4 u for the meal) in the dosage line instead of adding the 2 to whatever is the residual insulin?
  • It also does not add the suggested injection value for a high blood sugar with 0 carbs to any residual IOB?
  • Lastly I’ve found that occasionally the IOB just disappears ie it doesn’t count down all the way to being 0% after 4 hours. Eg last night I looked at the app which said I had 1.8 units left of a 3 unit injection, I looked 5 minutes later and it said I had 0% IOB. Perhaps I had entered something inadvertently?

I really hope someone might be able to help. The CGM has been fantastic and has changed my life but I’m losing confidence with the Diabetes360 App. I’ve contacted them and they say " I’ve got a point" but they can’t change the way how the App functions.

I am wondering if it just doesn’t deal with snacks. I know that “stacking” insulin is to be avoided but surely what I’m talking about is extra insulin for extra cho?


@LornaHadman hi Lorna, I am sorry I don’t use the app (Adappt LLC) but from what I read in your first bullet, the program has a bug. What you say, regarding the app recommending 0 units for the additional apple, is just wrong In the sense it should keep track of insulin -against-carbs. If you had a below target BS, and the apple was needed to raise blood sugar to target, that’s the only time a 0 unit recommendation would make any sense. I suppose there just aren’t that many safeguards for phone programs.

Good luck.

Hi Joe, thanks for your reply. Yes, I think you’re absolutely right, it just doesn’t make sense. I think I’ll just have to continue to use it as I have been, for the initial meal bolus calculation, then choose to inject when I know I’m eating more and add my dose for the extra cho to the IOB.

What fun we have!

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Hi Lorna @LornaHadman, I don’t use the 360 app either, but what you describe is very much like the algorithm used by the Tandem t-Slim x2 pump.
What I found in that which makes a significant difference in the recommended dose, is the target BG value. By modifying the target for what I believe are “reasonable” values for time of day that my overall performance is GETTING, but not there yet, optimal.

Hi there, thanks for replying Dennis. My target is set at 120 during the day and 150 overnight. I’m not sure I want to aim any lower than that.

I think the Dexcom 360 App just isn’t set up for extra food. Perhaps it’s just me anyway who’s greedy and wants to eat more after a meal! I suppose by my age I should know at the initial injection how much I’ll want to eat - maybe it depends on who’s cooking it!

@LornaHadman That’s funny. Maybe so, but I always “option the apple “ after lunch and to tell you the truth, I just manually bolus for it instead of asking my pump software’s permission.

Hi Lorna, I should have written better - I was suggesting a higher target after meals; this better follows how I expect my BGL to rise after food.
I just enjoyed snacks after a good supper and my pump recommended 0.25 units - I took a full unit to cover the carbs.

Thanks Dennis, I see what you mean, allow a higher rise after meals - it will come down. Your mentioning of quarter unit boluses has reminded me to check out if there is a pen available which gives these tiny doses. Sometimes when I’m exercising, I think a quarter unit would work well.

Thanks too Joe, you’re right, I’m the boss!