Delayed spikes after every meal?

I activated my new Dexcom sensor on Sunday (4/2), the first monitor I’ve had outside of my meter since the end of December (due to doctors office and insurance issues). Last year, my insulin needs were fairly stable and predictable as I eat a fairly predictable diet. Now, I’m having delayed spikes (2-3 hours after eating) with nearly every meal, seemingly regardless of carb/fat content. These are meals I’ve been eating for a year or more and did not react this way as of December. I’m still dosing up front what I had been, so I’m also using more insulin because these corrections doses are “extra” insulin I previously haven’t needed.

I’m at a loss as to what could be causing this or how to handle it (my husband thinks I’m just under more stress this week, but I’ve been under similar stress many times before :laughing:). My fasting/overnight numbers have been fine. I’m still on MDI, so right now I’m just chasing highs with shots at this point, which is incredibly frustrating since it takes a while (started spiking around 2:15 and two hours and two corrections later, I’m coming back into range). I don’t go very high; it’s just that my BG bumps up above my range and will just sit there (Dexcom was originally set to alert me at 160 but will be changing it back to my normal 140 so I can try to get ahead of these rises sooner).

Where do you usually start when your BG #s suddenly start behaving differently?


First I evaluate the basal. If I skip/delay a meal, does my BG stay more or less level in the absence of the food and bolus? If so, then I think my basal is about right for that part of the day.

If my BG rises after a meal and doesn’t come back down, I suspect I needed a larger meal bolus. If my carb counting was trustworthy and my basal is right, then it suggests I needed a stronger insulin:carb ratio, so I’ll make a tiny change to the number and see if that’s helping over the next few meals, and whether I need to adjust it a little further or go back.


Is your BG dropping lower faster right after a meal than in the past, and then rising at 2 to 3 hours postprandial?

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I feel like my basal dose is likely fine - stayed flat last night and woke at 95. But I’m thinking of fasting through lunch tomorrow just to see if things stay steady during the day as well.

To the I:C ratio - would it still be an ICR problem if the insulin seems to work fine initially, and only spikes later? I have only mild rises/stay flat for the first two hours after eating, and then it jumps.

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That’s a good question, and I’m not sure. :confused: I do feel like I’m not rising as much initially as I used to for some things.

With that pattern, I think about it as the carb digestion releases glucose at about the same rate as the activity of the insulin for the first two hours, but after that more carbs are still coming while the insulin is running out, so extra glucose is accumulating in the blood. The rise calls for more total insulin so all the carbs are covered, but some of the insulin may be needed later rather than at the beginning of the meal.

I would first try a slightly stronger I:C to see if the larger meal bolus is enough to control the later spike without causing the BG to go too low around 1 hour after eating. I’ve had success with that. But if you can’t take a sufficient amount of insulin all up front because of an early low, plan B is a split bolus or extended bolus or square wave. That is, take some insulin up front, and take additional insulin continuously for a couple hours (or as a second bolus maybe 1.5 hours after the first) to prevent the rise.

The basic concept from my CDE is “If your BG is too high, you need more insulin.” That’s the fundamental insight here: your BG is rising too high after the meal, so we think there wasn’t enough insulin to handle all the food. Then matching the speed of digestion with the speed of insulin action by something like an extended bolus (for a late peak) or a pre-bolus (for an early peak) is a refinement to smooth the dips and peaks in the BG line.


Thank you - that’s very helpful! I’m used to doing the split bolus for things like pizza and Chinese food, so was already thinking of trying that. I could also try adding a little more up front first to see if that’s the answer, especially since my doctor finally fixed my Novolog script so I can dose 1/2 units with my Echo pen again - I can really fine-tune things better with it (I’m still at relatively low doses).


Do you bolus for protein? This sounds exactly like the protein portion of your meal - gluconeogenesis. You’ll see it more pronounced when you eat higher protein meals. (This has happened to me from day 1, however.)

For me, every 8g of protein raises me about the same as 1g carb. So for that portion of my meal, I extend the protein bolus on my pump over the next 1:40.

With MDI, you could hold the protein bolus of rapid insulin until an hour/1.5 into the meal. Set an alarm.

I know of others that use regular insulin just for this purpose, it has a slower action over several hours, so it’s injected at the beginning of the meal to cover the protein rise 2-3 hours later.


Hmm, I’ve not bolused for protein before - I don’t generally eat high amounts of protein in one sitting, but I’ll check and see if there’s a pattern to do with protein going on here.

So far, my basal test has been beautiful (almost a flat line staying under 100), and upping my first bolus and catching the 2nd rise with more insulin and exercise has worked to keep me in range. I’m taking nearly double the insulin I was taking 4 months ago for the same foods. Since I have LADA, I’m beginning to think this might just be my honeymoon period finally coming to an end, though I’m still on what I feel like is a really low basal dose (6u/night)? :woman_shrugging: If it is that, I’d say I shouldn’t be too disappointed over a nearly 7 year run (diagnosed 7 years ago this month, actually).


You don’t have to share in response to these questions…but my other questions in addition to the great questions above would be: (1) have you gone on or off of birth control recently? (2) how long have you been seeing these delayed spikes? just a few days or on the order of weeks?

My carb sensitivity/general food sensitivity (including protein) now changes much more significantly every few days of my hormonal cycle than it ever used to. My carb sensitivity fluctuated quite a bit already…but now the amplitude is even bigger. I have other symptoms that also show me that my reproductive hormones are shifting from where they have been for the last 10 years and that adds a new fun factor in a lot of ways to my daily life.

My only other recommendation would be to double check pen expiration dates. I know that is a controversial POV, but in my experience…expired or nearly expired pens have less oomph in my body than fresher ones do. The doses just kind of fizzle out and disappear. My routines every day are very consistent bc I already have enough invisible variables to watch. Pen freshness has made a difference for me.

Good luck!

  1. No BC, but my hormones have been whacky off and on for years, which I finally began to manage with exercise last year, but I slacked off in March due to being insanely busy - still getting back on track. I do think hormones may be a factor here because my last period ended a week before I started my first Dexcom sensor, and it was abnormal for me; still seeing signs my hormones are out of whack now.
  2. I don’t know how long these spikes have been going on because I didn’t get my Dexcom prescription sorted out until a couple weeks ago and had been without my Libre since end of December. I’m afraid to admit…I barely finger tested that entire 3 month period due to a variety of factors. I have no idea what my BG was doing during that time, outside of being normal the few times I did check, hence why I could have missed a potential problem.

I did start a new pen in the midst of this, so I at least know it’s not that!

ETA: after examining my daily report in Clarity and talking with some others with diabetes, I’m beginning to wonder if it might, in part, be a basal issue - I’m not seeing rises while I sleep or in the morning, but seeing a climb around the same time every afternoon that I’m fighting into the night until I go to bed. I ate at 1:30 this afternoon, didn’t eat again til 6:30 and it was still climbing at 6 despite a correction at 5. Going to be doing another, proper basal test (the first was an inadvertent “I didn’t feel like eating for a while” thing :laughing: ).


Just an update - I split my long acting dose in half, switching to taking it twice daily and bumped each dose (so instead of 6u at night, 4u each evening and morning). Not only have I seen it make a huge difference in those rises I was seeing, but every time I forget my morning dose, they happen again, so I’m pretty sure that was the main cause. Now on to figuring out the best method to remembering that morning dose (and not just remembering it but also not second guessing whether or not I already took it)! :crazy_face: