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Peak blood glucose

J

Jonathantype2

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Hi
I can’t find some info anywhere. I wonder if you experts can help, please.

I am T2. Well controlled with Metformin apparently. No symptoms yet.

Wanting to learn what foods affect by BG most, I spent a fortnight with a Libre 2. Noting what I ate vs BG levels.

89% time in range (5-10 mmol) After meals usually back in range within two hours. So far so good.

But what I want to know is what is a reasonable peak level? Even if it doesn’t last long? Different foods clearly produce different peaks, but is a peak of 14 or 15 mmol/l to be avoided if possible? Or is that ‘normal’?

Thank you
 
Hello and welcome to our forum. Yes, a peak of 14 mmol/l is to be avoided. Food intake and timing are the two factors you can modify.

In my view the most important blood glucose readings are those that indicate the carbohydrate impact of the food you've just eaten. You’ll learn most from blood glucose levels just before you start a meal and then two hours later. The post-meal reading should be no more than 2 mmol/l higher than first and not higher than 8 mmol/l. If that's the case, your body dealt with the arrival of glucose in your bloodstream and cleared it relatively quickly.

By adjusting your meals, you can reduce those peaks to healthy numbers.
 
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Thank you very much. My levels are usually within the range you suggest, within two hours of eating.
So the peak levels I referred to are only brief. Are short-lived peaks a problem in themselves?
 
Hi @Jonathantype2 No, short lived peaks during the time before 2hrs after first bite occur in 'normal' non-diabetics too, since the insulin reaction isn't instantaneous. We measure at the 2hr mark because in those non-diabetics their insulin reaction has normally driven the BG levels back down to 'normal BG levels' by the 2hr mark.

Thus interim peaks above normal levels are not considered to be a problem.

Also CGM's said to be less accurate than a finger prick BG meter outside of normal ranges, so your CGM may be over-estimating in any case.
 
I think you need to think about both the height of the rise and the duration.

The range normally suggested by NICE - the National Institute of Health and Care Excellence - is for your blood glucose to be under 7.8 mmol/l two hours after eating, and within two mmol/l of your pre-meal value. Link below:

https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html

The purpose of testing before and after meals isn't to see "how high you go" but to see how effective your insulin response is at clearing excess glucose out of your blood. If you get a second reading at (say) 9.0mmol/l two hours after eating, that's clear evidence that your system could not cope with the level of carb (and resulting glucose) in the food you ate. So, if I got one, I would consider a 14 or 15 figure to be problematic.

What does the damage is elevated blood glucose over time. It doesn't have to be all that elevated, either - I had a good number of diabetic symptoms long before I was at "officially" diabetic levels. It seems to be the case that some people (like me) can't cope with even moderately elevated levels but others can tolerate higher BG levels without suffering immediate problems.

What are you eating regularly that produces these sorts of results?
 
Thanks

My downfall is muesli and / or marmalade on toast for breakfast.

Plain yogurt and fruit, and toast and peanut butter or cream cheese, seem to cause very mild and short - lived BG peaks. And obviously other proteins such as eggs, are the same.

But ‘No added sugar’ Muesli and marmalade on my toast both create peaks. Both in one meal gives me a high and longer lasting peak. I don’t do that any more!

I realise that my sensitivity could be a great deal worse, and I do consider myself fortunate.
 
Jonathantype2 said:
Thank you very much. My levels are usually within the range you suggest, within two hours of eating.
So the peak levels I referred to are only brief. Are short-lived peaks a problem in themselves?
Click to expand...
Congratulations on keeping your blood glucose readings in range most of the time.

Please be aware that even brief rises up to 14-15 mmols can cause damage over time. Unfortunately, type 2 diabetes ia a very individual disorder. None of us can tell you in advance to what extent yours are harmful..

If I were you, I'd invest in a glucometer and test strips to back up your CGM readings. If you keep a food diary alongside your BG records, you'll learn which meals result in these higher readings.
 
The thing is that it's all digestible carbs, not just sugar, that affect blood glucose. Those carbs are digested to glucose very quickly, which is why we'll see peak impact typically in the first hour after eating.

The foods you've given have various issues. Toast/bread is around 60% carb by weight, so a few slices will add a substantial amount of carb. Muesli, even the "no added sugar" sort, is around 70% carb.

Fruit is high in fructose, another sugar. Some yogurts have added sugar on top of the natural lactose. If you are regularly eating this type of food, I think your current levels are where I would expect them to be.

This website is a good source of info on carbs and sugars in food:



It leads me to think that maybe reducing your carb intake would help greatly in reducing your BG levels. If you haven't seen it before, this is a good guide, written by one of our forum members:


The Nutritional Thingy

There’s a few things you should know. 1. Practically all carbs turn to glucose once ingested , so not just straight sugars, but starches...
josekalsbeek.blogspot.com

Best of luck, and ask about anything that's not clear.
 
Jonathantype2 said:
And obviously other proteins such as eggs, are the same.
Click to expand...

I would not expect proteins to significantly raise your BG.
For example, hard boiled eggs are usually a safe snack because of minimal carbohydrates.
Also cold meats such as chicken and ham.
Dairy such as cheese.

Just checking, what is your source for the "obviously"?

Asking for my pancreas.
 
Perhaps @Jonathantype2 was looking at information for Type 1 diabetics, for whom (in the absence of carbs, they have to bolus insulin for Proteins.
Though as Type 2's we just ignore the affect of proteins on Blood Glucose since it is so minute!
 
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