CGM frustration; Proper insulin dosing

I got a DexCom CGM a few months ago, and it’s been making me extremely frustrated. I guess it’s good that it’s forcing me to re-look at my insulin doses and how I eat, but the “control freak” part of me is going really crazy. It’s hard for me to not overcorrect when I go high, and not panic when I see double arrows in either direction.

I’ve been trying to get the dosage right for eating bagels. I’m running a marathon in a couple of months, and after eating low-carb for so long, it’s been an adjustment. I normally do a 1:10 ratio for carbs, and one bagel has 48 carbs. So today, I gave 5 units of insulin and waited 22 minutes. I was 121 when I ate the bagel, just plain and dipped in black coffee.

My sugars stayed steady at 120 until about an hour and 15 minutes after eating the bagel, when my sugars started going up. When it got to 188 and two arrows straight up, I gave 2 units of insulin. (1 unit typically brings me down about 50 points.) It kept going up, and I let it keep going up until it got to 282 (which was more than 2 hours after eating the bagel), at which point I gave another 4 units. About 20 minutes after giving the 4 units, I’m finally going down (angled arrow down) and currently am at 253.

Why is the increase so delayed? And why does it take so darn long for it to come back down? The whole episode of being high is probably going to span around 2 or 2.5 hours, and this has been typical of times when I’ve gone high. Yesterday, for example, I was high for about 3 hours before my sugars dropped dramatically (double arrows down).

Is that normal for other people? It drives me berserk, and it is so hard not to give more insulin when it doesn’t seem to be coming down. I have to fight the urge to not give another shot.

Are you doing your insulin based on your CGM?

I test before I take insulin, since the CGM is NOT 100% accurate. Once I take my insulin for correcting a high, I ignore my CGM until an hour later. If it’s still showing me as high, then I test again.

I leave mine on vibrate so that it doesn’t beep until I’m below 3.1mmol/L and though the vibrate can be loud, it’s easy for me to ignore it after I’ve corrected a high, etc.

For lows, I never rely on the CGM to see if I’m coming back up. I treat, wait 15 mins, test. Even if my CGM has been beeping that I’m going lower I wait and test 15 mins after finishing my glass of juice or whatever.

Sometimes my CGM says I’ve been low for an hour, when really I had a slight low (3.5) and got it back up and have been hovering around 5.4mmol/L for the rest of the hour. Sometimes it says I’m 8.2mmol/L when I’m 7.4mmol/L. Just have to learn to take it all with a grain of salt.

For bagels I find the best are cinnamon bagels. While I hate when people say cinnamon can cure diabetes, I do find it helps my levels stay more balanced so I do use it often instead of sugar in tea, on my oatmeal instead of syrup, etc. I’ve never had an issue with my BGs when eating cinnamon bagels. In fact, I once ate three in a row but had only taken enough for one bagel…my BG barely moved!

Thanks, @natrie. I did test it when it got to 290 on the CGM (which is when I was 282 according to my glucometer). I don’t do that EVERY time, but most of the time (especially for big corrections) I do.

I think you’re right about the lows, though. I’ll have to do my best to do what you do, and just stop paying attention to it. (Easier said than done, though, especially since I have pretty serious hypoglycemic unawareness.) I do agree with you, though; I have noticed the same thing.

And it WAS a cinnamon bagel!! LOL. I have the same experience with cinnamon that you do - when I put it in my coffee grounds, my sugars are generally very stable. But these bagels are really messing with me. I don’t know if I need to start treating them like pizza, and giving an additional shot an hour later.

But it’s really the duration of the highs that’s driving me crazy, because it just seems like a really long time to have steady high sugars. I will test more frequently during those times, though; I think your suggestion is right on.

I would test anytime it says you’re out of your “target” area, even if it only says your slightly high before taking insulin but once you treat, give it some time before you test and take more insulin. My level will sometimes rise a bit higher before it starts to come down, insulin does have a delay of about 15mins or whatever, but when it does it starts dropping closer to normal and if after an hour or so it’s still high than I take a correction based on that number.

You might also need a new correction ratio. I find that mine take longer to come down, but I’m also almost 4 months pregnant so it’s an insulin resistance thing for me.

Definitely; I will do that. Thank you, @natrie. And congrats on your pregnancy! :slight_smile:

Thanks and good luck with the correcting @MariaKhristine! :slight_smile:

Hi MariaKhristine,
I’ve been there many times! Here’s some brainstorming about your bagel adventure, maybe something will be helpful. :slight_smile:

  1. It’s fairly likely that your carb count was on the low side. I think bagels are usually 55-70g, depending on size. Best way to be sure is weight one of them some time. So probably you needed an extra 1 or 1.5u.
  2. bagels spike my BG a lot compared to other foods, so I would expect a spike after eating it, unless I very slowly nibble it over an hour or so (no fun). An hour and 15minutes is exactly the right timing for the spike.
  3. when you say bg started to drop 20 min after the 4u bolus, I think this has nothing to do with the 4 units. Probably it doesn’t have that much to do with the previous 2 units either. Likely that was just the original bolus finally catching up with the bagel. Insulin takes freaking forever to kick in.
  4. after this episode, did you keep track of how many carbs you had to eat to avoid/treat a low? In the next 3-4hrs. I bet it was about 4u worth?
  5. when “proactively” treating highs like this, make sure not to give more units total than are justified by your BG. Like, when you were at 280, that only takes a bit over 3u to bring down. And you already had most of 2u on board lined up to go. So you probably didn’t need more than 1u extra at that point.
  6. if you use a pump, watch the insulin on board as well as the Dex. If iob is ever less than required to bring your BG down, take more correction to make up the difference. If, after you know your food is done digesting (2-3hrs?), the iob is bigger than required to bring down your BG, maybe take extra food to make up the difference and avoid a low.
    Good luck! :slight_smile: These judgment calls are crazy hard.

Thanks @aitrus. I do have an endo appointment next week, so hopefully I’ll get some ideas about how to better handle this.

Lots of good advice here. I just want to add that I also notice it seems like it takes forever to correct a high. Try to make sure you give your insulin enough time to start working. My CDE always told me bagels are tough because they are so dense. Keep working at it and you will get it.

Maria, I am so with you in your frustration. Sounds like you are telling my story. Although i could not live without my CGM, I feel like I cater to it and am constantly correcting only later to crash from “stacking”. Bagel were always a no-no for me. They take me higher than double chocolate cake. If I were you I would do a square wave bolas. that usually helps me with pizza. Good luck in the marathon.

I find there is a limit to what I am willing to do to accommodate certain foods in my diet. Bagels are definitely one of them. If it frustrates you, if you cannot conquer it, it’s not worth the effort. There are so many other wonderful foods - I would never dream of wasting my very precious time on a bagel.

Disclaimer - I follow a ketogenic diet. CGMs rock.

Perhaps I should be doing more finger sticks with my CGM. I did recently upgrade to the newer system that is supposed to be even more accurate. I think it’s called 505. It’s supposed to be the same as what they are using for the “artificial pancreas”. I still go much higher than I would like after anything but a small meal. My A1C’s have been 6.5, 7 and 6.2 and that is new for me. For that I am grateful. I recently started using the Nightscout system which I really find helpful and convenient. Lot’s of times I get weary of living with Diabetes. Over 40 years for me now!

I wish someone would come up with something that would make diabetes treatment easier. Seems with all these new devices, it takes more time,finger pokes,energy, stuff attached to us, and money to try to get better control. Is all this extra finagling worth it really sometimes I wonder?

I hope you can figure it out I really do.

37 years with this has taught me though that what works today may not necessarily work tomorrow and once you think you got it figured out, all hell breaks loose.