Bolus issues - excellent glucose, then small spike

Hi all,
I think I have finally found a great basal amount of Lantus that keeps my glucose well controlled during the night with a perfect reading in the morning. However, as I have tried to really tighten control lately and am now using a Freestyle Libre, I’m confused by some postprandial results I’m getting. I eat low carb and after taking my NovoRapid with breakfast, I have very stable results (wonderful!) in the hours following my meal (around 97-100) in the first hour, but then after around 2 or 2.5 hours post-meal, my glucose slowly starts to climb again - usually reaching around 130 (but sometimes as high as 140 or 150) by the four hour mark. It seems like the duration isn’t working and that there’s not enough insulin for the long haul to stay in perfect range before it’s time for my next dose of insulin.

At first I thought I should try to raise my Lantus, but doing so by two units gave me multiple nighttime hypos. I think my current Lantus dose is right, at least as far as nighttime control is concerned (really stable).

I have an appointment with my endo to discuss this soon, but in the meantime, I was curious to hear if others have experienced really positive postprandial glucose levels followed by a small spike that are not caused by heavy carb load (it’s not like I’m eating pizza!). I haven’t really noticed this pattern before because I only recently switched to CGM.

Since you are eating low carb, you are probably eating more protein and fat which do also raise your blood sugar but more slowly than carbs. You could try splitting your mealtime bolus and take 1/2 before you start eating and 1/2 a hour or so later.


You could try using Regular (sold under brand names like Humulin R, Novolin R, Actrapid, Novolin GE Toronto, Relion R, etc.) insulin instead of NovoRapid. It has a duration and peak that should better match eating low carb meals. You could also try splitting your Lantus dose, so that you can take different amounts for day and night. Levemir is a basal worth trying if you want to do this, as it has a shorter duration than Lantus (usually lasts 10-12 hours at smaller doses) making it very conducive to splitting.

My body acts in the exact same way. I prebolus fast acting Humalog 15 minutes before my low carb meal and then 2.5 hours later my BG starts to rise. The way I control that, since it takes 26 minutes for my fast acting insulin to kick in is to take an additional dose of fast acting insulin 2 hours after I eat. My BG will rise to 130-135 and it takes me 1 unit of fast acting insulin to drop 20 points of BG so I take 3 units to keep me around 70 rather than having to deal with a rise. It is also interesting that this issue is more prevalent during the warmer Summer months than during Winter. Do not touch your Lantus dose if it works for you during the night.

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Thanks so much, that does sound really similar to what I’ve been doing (taking a tiny second dose 2.5 to 3 hours after my meal) to perfect my bg. Thanks for the word of encouragement about sticking with my Lantus dose; it really is working super well at night and it took forever to achieve that! (love seeing that straight line on my daily graph!).

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