Why does blood sugar sometimes rise 3-4hrs after dinner?

[littlevoice359]

Hello all,

I was diagnosed with Type 1 diabetes in Dec 2018 and I am still getting to grips with the condition. Mostly, I find it infuriating and exhausting because of the almost constant need to make decisions based on partial information. I wear a Libre sensor, along with a Bubble Mini sensor that sends data to xDrip on an Android phone. This lets me keep track of my blood sugar trends between meals and when I am asleep. My doctors say my blood sugar control is excellent ( A1C has been consistent at 50 for the past 3 clinics and my time-in-range is 97% ), though personally would like it to be better.

I still struggle with one issue in particular, which is that my blood sugar will sometimes start to rise 3-4 hours after I have eaten dinner. If I do not notice the gradual rise, I find that my blood sugar going to bed could be at or over 10. This forces me to take a corrective dose of NovoRapid, but in doing this, I run the risk of sending my blood sugar too low while I am asleep. But, if I do not take a corrective dose, my blood sugar could quite easily remain elevated all night, which is not a good thing. A bit of a Catch-22 situation…

I think the problem is somehow related to the amount of protein and/or fat in my evening meal? I have seen hints to this effect in various pieces of literature I have read, but I have not yet seen the issue explained in any kind of concise way.

Currently, as a stop-gap containment, I have configured xDrip to alarm if blood sugar rises above 8 during the evening and, if it does, I then confirm with a finger-prick test and take 1-2 units of NovoRapid, depending on how steeply blood sugar is rising. Rather too much guesswork involved here, though, for my liking. I would like to understand the mechanism involved so that I could better anticipate when the rise is likely to happen. This would let me feel more comfortable about taking a corrective dose of insulin before blood sugar rises too high.

I hope I have explained my dilemma sufficiently well?

Many thanks in advance for any advice or insight you can offer!

 

[Robin]

Hello, and welcome to the forum. You may well be right, a meal heavy in protein and fat will tend to digest more slowly, or slow down the digestion of any carbs you had with the meal. If the meal was relatively low in carbs, your body could be converting some of the protein to glucose, which it does more slowly. It will also use fat for fuel, in the absence of readily available carb, as well. I often find with a breakfast of just eggs, I don’t need any insulin at the time,but find my BG levels rising 2-3hrs later.
The other thing to look at is your basal. When do you take it? And which sort do you take? If you take it at bedtime, and it’s a supposedly 24hr one, you may find it’s actually running out or running low by the time of the next dose, so your evening mealtime insulin is having to do the job of a basal as well. (This won’t apply if you’re on Tresiba which has a much longer profile, or if you take your basal in the morning).

 

[Bruce Stephens]

My doctors say my blood sugar control is excellent ( A1C has been consistent at 50 for the past 3 clinics and my time-in-range is 97% ),

I think anybody would agree: that's excellent. Sure, a lower HbA1c might be better, but 97% suggests low variability, too, which is likely better than a lower HbA1c with a higher variability.

I think the problem is somehow related to the amount of protein and/or fat in my evening meal?

Could be. Maybe for a larger than usual meal you could try a unit or two of bolus an hour or so after eating? (So before you actually see any rise.)

 

[littlevoice359]

Hello, and welcome to the forum. You may well be right, a meal heavy in protein and fat will tend to digest more slowly, or slow down the digestion of any carbs you had with the meal. If the meal was relatively low in carbs, your body could be converting some of the protein to glucose, which it does more slowly. It will also use fat for fuel, in the absence of readily available carb, as well. I often find with a breakfast of just eggs, I don’t need any insulin at the time,but find my BG levels rising 2-3hrs later.
The other thing to look at is your basal. When do you take it? And which sort do you take? If you take it at bedtime, and it’s a supposedly 24hr one, you may find it’s actually running out or running low by the time of the next dose, so your evening mealtime insulin is having to do the job of a basal as well. (This won’t apply if you’re on Tresiba which has a much longer profile, or if you take your basal in the morning).

Hi Robin,

Thanks for that. I take (15 units Toujeo) basal insulin at 10:30pm each night. Originally I was on Lantus but with that, blood sugar pretty much rose each evening regardless of what I ate. At least with Toujeo I have evenings and nights where blood sugar is almost dead flat, so this is why I think the issue is related to meal contents.

The frustrating thing is that I see consecutive evenings where dinner content is virtually identical but blood sugar is fine one evening and less so the next.

That seems to be a characteristic of Type 1 diabetes - there is so much going on about which we have no control and for which we have no data. This makes it very challenging to always make informed decisions.

Again, thanks for your reply.

All the best.
Willie

 

[littlevoice359]

I think anybody would agree: that's excellent. Sure, a lower HbA1c might be better, but 97% suggests low variability, too, which is likely better than a lower HbA1c with a higher variability.

Could be. Maybe for a larger than usual meal you could try a unit or two of bolus an hour or so after eating? (So before you actually see any rise.)

I usually take bolus at least 15 minutes before I eat, longer if my blood sugar is high. That helps quite a bit. Also, I include a glass of milk that I can drink or not, as the case may be, depending on how my blood sugar reacts after eating. That, and a walk after dinner all help avoid large spikes. But, I am still left with an issue 3-4hrs after eating. Not a problem unless I don’t catch it in time…

 

[Robin]

That seems to be a characteristic of Type 1 diabetes - there is so much going on about which we have no control and for which we have no data. This makes it very challenging to always make informed decisions

Have a look at this! 42 factors that affect Blood Glucose. No wonder we have trouble!

42 Factors that affect BG

A useful list for when you're making that 'piece of cake' calculation :) ETA: Article about the table: https://diatribe.org/42factors

forum.diabetes.org.uk

 

[trophywench]

What you are seeing is common, usually known as 'The pizza effect'.

See https://diatribe.org/pizza-and-blood-sugar-control-not-quite-easy-pie

 

[Inka]

The frustrating thing is that I see consecutive evenings where dinner content is virtually identical but blood sugar is fine one evening and less so the next.

My instinct was you had a basal issue, and that statement makes me lean even more towards basal problems. Have you tried taking your Toujeo slightly earlier in the evening?

Most importantly, your control is excellent. Type 1 will burn you out if you obsess over perfection. Perfection is impossible. Type 1 needs to fit into our lives not be the focus of them to such an extent that we forget to live.

 

[littlevoice359]

What you are seeing is common, usually known as 'The pizza effect'.

See https://diatribe.org/pizza-and-blood-sugar-control-not-quite-easy-pie

That was an interesting read and explained a lot. I recently had a homemade pizza for lunch to use up some tortillas. Caused slightly low sugars immediately after then a spike hours later, exactly like the article predicted. Thanks so much for passing along this info

 

[littlevoice359]

The frustrating thing is that I see consecutive evenings where dinner content is virtually identical but blood sugar is fine one evening and less so the next.

My instinct was you had a basal issue, and that statement makes me lean even more towards basal problems. Have you tried taking your Toujeo slightly earlier in the evening?

Most importantly, your control is excellent. Type 1 will burn you out if you obsess over perfection. Perfection is impossible. Type 1 needs to fit into our lives not be the focus of them to such an extent that we forget to live.

I’m beginning to realise that and will need to try better to relax a bit more. Doesn’t help that I’m an engineer by profession and so used to fixing issues so they stay fixed. But clearly T1D can’t be fixed, as such.

 

[Inka]

I’m beginning to realise that and will need to try better to relax a bit more. Doesn’t help that I’m an engineer by profession and so used to fixing issues so they stay fixed. But clearly T1D can’t be fixed, as such.

Managed rather than fixed 🙂 And you’re managing it very well - be proud. Type 1 is a moving target. Things change - then change back again just as you think you’ve sorted them; injection sites can be variable; digestion can be variable; 42+ factors can affect blood sugar.

This is the real nuisance of Type 1. People think it’s having to have injections or having to count carbs, but it’s the ongoing ‘trying to pin jelly to a wall’ aspect that’s most tiring.

Do experiment with moving your basal injection time though. I have a pump, but when on injections I find somewhere between evening meal and bedtime works best rather than last thing.

 

[littlevoice359]

Good point about basal timing. As it happens, I did experiment with this some time back, when I was on Lantus and had put it out of my mind when my doctor switched me to Toujeo (because it doesn’t wear off as quickly). It may indeed be time for me to reconsider that aspect of things.

 

[littlevoice359]

Inka. I took your suggestion on board and moved my basal injection to 8:30pm. Already I am seeing much improved stability throughout the evening and during the night. Maybe that's just beginner's luck, but I'm keeping my fingers crossed that this trend will continue. Injecting at 8:30pm is more convenient in any case as it means I don't have to be so regimented about when I go to bed. Thanks again for your suggestion.

 

[Inka]

That’s great news @littlevoice359 !

 

[everydayupsanddowns]

Already I am seeing much improved stability throughout the evening and during the night. Maybe that's just beginner's luck, but I'm keeping my fingers crossed that this trend will continue.

Great to hear @littlevoice359 - long may it continue 🙂

 

[littlevoice359]

Hi folks.

Just a quick follow-up on this item. Now that roughly 7 weeks have elapsed since I made those changes to my regime, I took a look again this morning to see what, if any, effect the changes have had. The results are, to my mind, positive and encouraging. I won't bore you with too many details, but suffice to say that I am controlling fat and protein a little better now.

Firstly, now that I know what the fat/protein content is, I am better able to decide if additional bolus is needed some hours after eating. Now when I inject basal insulin in the early evening, I do a finger-prick test to check if I need to take bolus insulin also. I am still surprised occasionally, but mostly I know beforehand what to expect.

A review of my before/after AGP graphs lets me see that my blood sugar is somewhat flatter now in the evenings, which is what I was trying to accomplish. Also blood sugar during sleep has remained relatively flat, so there are no negative effects from the changes that I can see.

So, all good. Again, a big THANK YOU for your help with this! 🙂🙂

 

[SB2015]

Hi folks.

Just a quick follow-up on this item. Now that roughly 7 weeks have elapsed since I made those changes to my regime, I took a look again this morning to see what, if any, effect the changes have had. The results are, to my mind, positive and encouraging. I won't bore you with too many details, but suffice to say that I am controlling fat and protein a little better now.

Firstly, now that I know what the fat/protein content is, I am better able to decide if additional bolus is needed some hours after eating. Now when I inject basal insulin in the early evening, I do a finger-prick test to check if I need to take bolus insulin also. I am still surprised occasionally, but mostly I know beforehand what to expect.

A review of my before/after AGP graphs lets me see that my blood sugar is somewhat flatter now in the evenings, which is what I was trying to accomplish. Also blood sugar during sleep has remained relatively flat, so there are no negative effects from the changes that I can see.

So, all good. Again, a big THANK YOU for your help with this! 🙂🙂

That is great news @littlevoice359 . It is amazing what a big impact some small changes can make.

 

[nonethewiser]

Hi folks.

Just a quick follow-up on this item. Now that roughly 7 weeks have elapsed since I made those changes to my regime, I took a look again this morning to see what, if any, effect the changes have had. The results are, to my mind, positive and encouraging. I won't bore you with too many details, but suffice to say that I am controlling fat and protein a little better now.

Firstly, now that I know what the fat/protein content is, I am better able to decide if additional bolus is needed some hours after eating. Now when I inject basal insulin in the early evening, I do a finger-prick test to check if I need to take bolus insulin also. I am still surprised occasionally, but mostly I know beforehand what to expect.

A review of my before/after AGP graphs lets me see that my blood sugar is somewhat flatter now in the evenings, which is what I was trying to accomplish. Also blood sugar during sleep has remained relatively flat, so there are no negative effects from the changes that I can see.

So, all good. Again, a big THANK YOU for your help with this! 🙂🙂

Wow well done.

Trouble is it's widely thought that it's just carbs that raise bg without considering protein & fat, with type 1 they certainly do anyway as I've also experienced myself.