Lantus doesn't last 24 hours- maybe?

I’ve been doing MDI for the last few months, with 2 Lantus injections per day (9 am dose of 13 units and 9 pm dose of 12). This works well throughout the day, but my blood sugar shoots up to 200 or so around 10-11 pm, and then usually slowly decreases throughout the night (sometimes even dropping low).
The increase is not because of belated carbs from dinner. It happens consistently, and I’m guessing it’s because the Lantus isn’t lasting the full 24 hours. It’s weird that this doesn’t seem to be an issue in the morning though.

I’m not really sure how to handle it because I clearly can’t increase my evening Lantus (it’s probably too high as it is). I’m currently bolusing a couple units of humalog, but then I generally wake up to my cgm alarm around 5 am. I also don’t like the idea of bolusing because my basal isn’t correct. If I decide I’m ok with bolusing for this reason then I’ll probably lower my basal rate at night.

Has anyone else struggled with something similar? How did you handle it? I’ve been on the pump in the past, and while that can resolve issues like this, I had other problems while on it. I needed a break.

It might not be belated carbs from dinner, but what about protein from dinner? What time do you eat dinner? How many grams of carb and grams of protein do you usually have for dinner.

I’ve noticed a number of times that my BG increases quite a bit about five or six hours after dinner or a high protein snack, though not nearly to 200. I suspect that it is the protein converting to glucose that causes it, but will have to make note of additional times before I draw a definite conclusion.

@Uff_Da offers a credible possibility. Have you ever used Regular insulin? It has a slower onset, slower peak and a longer duration than the rapid acting analog insulins like Humalog and Apidra. Taking a few units of Regular might help in this scenario. I use a pump and I take an extended bolus with every meal to cover protein and fat. I also take an immediate bolus for the carb content of the meal. I know Dr. Bernstein uses Regular this way and it should help with than 10-11 p.m. high.

Thanks for your response, but I’ve solidly ruled out that it’s not related to dinner. I’ve even eaten at as early as 3 and then fasted to double check. This is a consistent problem and my diet varies enough that it wouldn’t be if it was related to my dinner.
I’m guessing it’s either that I require more basal at this time than the Lantus is giving or that the Lantus isn’t lasting the full 24 hours.

Then I guess you’d have to rely upon doing a basal test, covering the whole 24 hours with fasting for periods of time. I really don’t know how you’d best do it with taking basal twice a day. I only take mine once a day so basal testing is pretty straight forward. And I take my basal just after dinner, so if it runs out an hour or two early, it is not much of an issue, since I always bolus for dinner about that time anyway.

I best leave it to someone else who also has done basal twice a day on MDI to offer specific suggestions. I’m sure interpreting results would be a bit more complex.

I wonder if Levemir would work better for you than Lantus, if it is that you need more of a peak. For most people I understand that it does have more of a peak than Lantus. Or as Terry4 said, maybe using Regular at night might work better. You might have to change the timing to get the peak to hit your peak need for basal, if that’s the case.

Change when you take Lantus. I’m on Levemir because it isn’t supposed to last 24 hours and it does peak: two factors I take advantage of. I was on Lantus (and pumped for several years). When splitting the dose, you don’t have to split it in half and you don’t have to take it morning/ night. I am LADA, so my insulin needs throughout the day vary greatly. I take 11 units at noon and 8 units before bed, but I may tweak the amounts or the timing ( earlier/later) to try to match my needs more closely. Play with it.

That’s an interesting suggestion Mary. I switched to two injections because I was dropping low at night with all the Lantus being given at one time of the day (Lantus has a small peak a few hours after injection). I ended up with the split dose I have because it seemed to work for me during the day (this is very important for me because I want my levels in range while I’m at work).

Id hesitate to give my Lantus dose around dinner because I don’t really want to be dealing with a post meal spike and Lantus issues at the same time. Maybe I could give it in the afternoon though. Lantus’s small peak might be helpful at dinner time anyway.

Thanks for your reply :slight_smile:

I’ve found that my levemir doesn’t last for 24 hours, even though my endo was so sure that it did. For me, it last more like 18 or 20 hours. Everyone seems to be so different as far as what kind of dosing works. You could maybe try checking your bg aroun8:30 or 9 pm, which might be around the time its starting to shoot up. Even if you had a carb-snack around 8 or 8:30 with some rapid, it would probably help a lot because the rapid will then be in your system before the background insulin would start wearing off.

Figure out when you start spiking. Figure out when basal insulin goes into effect and when it peaks. Match curves.

Curves may change.
Potency of insulin may deteriorate. Fresh from a new box may be more potent.

Do what works, even if it’s not textbook. Switch to fresher insulin, even if it seems wasteful.

Thanks again for the recommendations. I switched to 1:30 pm for my second Lantus dose, and that’s resolved my spike after 10 pm. We’ll see if any new patterns pop up, but at least this particular one is resolved!


have you thought of switching to Tresiba?

1 Like

Tresiba might be helpful

I was on the pump until a few days ago. I just can’t deal with the bent catheters and bubbles getting in my reservoir and line. I recently went on keto and when I got bubbles in my line and my sugar would go up and I had to take insulin which threw me out of ketosis. So I went back on Lantus and it doesn’t last 24 hours for me either. So I am taking 30 units at 6 am and I know it takes 4 hours for it to work, so should I take the second shot at 20 hours?

Thanks Catherine

Most people split lantus doses at around 12 hours, two doses per day. It’s still not perfect, but it means that only part of your dose wears off at once, and works well enough for many. You also don’t need to split it evenly, depending on your needs. I don’t think taking your insulin every 16 hours would work well for most people, because eventually you’d need to take your shot in the middle of the night…