Glucose spikes and diagnosis of diabetes

[daski]

Hello All
Joined forum as I am being confused by some info.

Just a short summary of findings and symptoms: my HbA1c is normal, fasting glucose normal as well, I am super tired in general, extremely sleepy, get moderate amount of brain fog, tingling in hands and sort of being not well (these happen only after big meals, if I eat little frequently or don't eat I am perfectly fine). I had episodes of low blood sugar where I felt extremely poorly (finger prick reading of below 4, the lowest I noticed was 3). Diabetes type 2 running in family. I bought as well Libre 3 to monitor what is happening which indicated several spikes after meals between 11 up to 15 (some of them were doubled checked with finger prick readings).

I am a bit confused about this statement when it comes to diagnosing diabetes:
Random plasma glucose of 11.1 mmol/L or more in the presence of symptoms or signs of diabetes.

So following this I would guess that I may have some symptoms. I consulted all graphs and findings and been told that these spikes are normal. Maybe I am too mathematical but how am I being told that 14 is fine while 11.1 is the boundary of normal?

 

[KennyA]

Hi and welcome.

When you say your HbA1c is "normal" what is its value, please? A "normal" HbA1c will be under 42. However diabetic symptoms can appear (for some of us) almost as soon as BG leaves "normal" range.

And how have you had your plasma glucose tested? That's not the same as a fingerprick test. A "blood sample" can be plasma, capillary (for fingerprick), or whole blood, and these will return different values. I've never had my plasma glucose tested and I can't think of anyone who has - there will be people on the forum who have.

Rises in blood glucose after meals are perfectly normal and shouldn't (in my opinion) be called "spikes" which makes them sound scary, unexpected, and unusual. Have a look at this paper which helps to establish what "normal" looks like for the new generation of CGMs, as tested on non-diabetic people. You'll see that significant rises after carb-containing meals are to be expected for people without diabetes, let alone those of us with.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769652/

All that said, you are reporting some things that are often quoted as being symptoms of T2 diabetes. The issue is that they can be symptoms of other things as well, and you really need to talk to your doctor about that.

 

[daski]

Thanks @KennyA , mine is 36. This article looks good, I will have a read.
I assumed that plasma glucose test is one that is done when your blood is taken (quite surprised you haven't had one as this is most default one I think that GP's use). Description states this:
A fasting plasma glucose test, also known as a fasting glucose test (FGT), is a test that can be used to help diagnose diabetes.
Furhermore as far I understand it is usually higher than capillary or CGM - meaning that result from plasma would be even higher than the one you have on CGM graphs or standard finger one.

Update after reading the article:
1. None of graphs go more than 180mg/dl
2. Percentage of time spent in different glucose ranges 140-168 max range
So now comparing to my level indicated by Libre and finger test of 14.0 mmol/L = 252.25 mg/dL so hm... rather not in any healthy range - plasma glucose would be even higher (5-15% more as far I could find).

 

[JoKalsbeek]

Hello All
Joined forum as I am being confused by some info.

Just a short summary of findings and symptoms: my HbA1c is normal, fasting glucose normal as well, I am super tired in general, extremely sleepy, get moderate amount of brain fog, tingling in hands and sort of being not well (these happen only after big meals, if I eat little frequently or don't eat I am perfectly fine). I had episodes of low blood sugar where I felt extremely poorly (finger prick reading of below 4, the lowest I noticed was 3). Diabetes type 2 running in family. I bought as well Libre 3 to monitor what is happening which indicated several spikes after meals between 11 up to 15 (some of them were doubled checked with finger prick readings).

I am a bit confused about this statement when it comes to diagnosing diabetes:
Random plasma glucose of 11.1 mmol/L or more in the presence of symptoms or signs of diabetes.

So following this I would guess that I may have some symptoms. I consulted all graphs and findings and been told that these spikes are normal. Maybe I am too mathematical but how am I being told that 14 is fine while 11.1 is the boundary of normal?

You're giving a lot of information, and believe it or not, it still doesn't paint a complete picture. When your blood glucose goes high, up to 15 and some such, what happens afterwards? Does it crash down suddenly into hypo territory? Just wondering. There are other blood glucose issues than T2, after all, and who knows.... Reactive Hypoglycemia might be on the table? Also, the symptoms you describe could be from other issues... Have you discussed any of this with a GP? Maybe get a MOT scheduled, get thyroid function and such done as well. Just get everything checked, from (thyroid etc) hormones to possible mineral or vitamin deficiencies (D, the many B's especially), see whether anything sticks.
Good luck,
Jo

 

[daski]

@JoKalsbeek thank you for reply, It has been all discussed with GP. All other factors were considered and results normal (hormones, minerals etc.) the issue is clearly related to food consumption (type and quantity). Reactive Hypoglycemia is still on the table and under investigation. Basically my simple question is: should person without diabetes have any (whatever the source CGM/finger/blood) glucose readings of more than 11 at any time. From all information I was able to find this is not normal while I was told during consultation that they are ok - this is why I am so confused. I do understand that diagnosis takes into consideration other factors or tests but still - if there is a range specified for norm (random <11) I fail to understand why 14 would be ok.

 

[Melgar]

@daski I would say that a rise to 14 mmol/Ls is marginally not normal. Not normal because a healthy response by the pancreas to carb/sugars consumption would see a lower peak.
The pancreas has a biphasic insulin response to food consumption. The first phase , which happens quickly and comes from a small reservoir of insulin, usually deals with the food we eat. If this first phase fails to bring down the rising blood sugars, the pancreas then produces and secretes a second phase response. This 2nd phase insulin secretion continues until the blood sugar is normalized. With reactive lows the pancreas over produces insulin and blood sugars go low. This is common, and not of great concern for someone not taking blood sugar lowering meds or insulin. With Reactive Hypoglycemia however, the pancreas overproduces insulin to such a degree that blood sugars can go dangerously low.
So, your 14 mmol/L blood sugar level depends on the amount of carbs you ate. Even so, I would personally suggest that a rise of 14 is marginally not normal, and that you are sensitive to carbs. It may also suggest that your 1st phase insulin response is weak.
The important aspect to our insulin response is how long it takes your pancreas to bring down your blood sugars to within a couple of mmol/ls of your pre blood sugar levels before you eat. That is the determining factor as to whether you are coping with the amount of carbs you are consuming. Other factors, regarding the results of your HbA1c test can be skewed by the number of low sugar episodes you are having after food. Low blood sugar episodes will bring down your overall HbA1c results and may mask what is actually going on with your blood sugars.

Low blood sugar symptoms , anything <3 mmol/ls will likely bring on low blood sugar symptoms, like sweating, feeling uneasy / anxious, headaches, shakey, tingly. Nausea. As your blood sugars drop, the liver will usually kick in and begin secreting glucose to bring up the blood sugars. At the same time signalling between your liver and pancreas will stop your pancreas from secreting insulin and your blood sugars return to ‘normal’. In Reactive Hypoglycemia this signaling can fail, hence the serious low blood sugar episodes.

Edited changed 11 to 14 and added sentence - weak first phase

 

[JoKalsbeek]

@JoKalsbeek thank you for reply, It has been all discussed with GP. All other factors were considered and results normal (hormones, minerals etc.) the issue is clearly related to food consumption (type and quantity). Reactive Hypoglycemia is still on the table and under investigation. Basically my simple question is: should person without diabetes have any (whatever the source CGM/finger/blood) glucose readings of more than 11 at any time. From all information I was able to find this is not normal while I was told during consultation that they are ok - this is why I am so confused. I do understand that diagnosis takes into consideration other factors or tests but still - if there is a range specified for norm (random <11) I fail to understand why 14 would be ok.

That's why I asked whether your bloods drop like a stone afterwards. In RH, the insulin response can come in late, driving your blood glucose up while your pancreas is twiddling thumbs. And then it wakes up, scrambles like mad to get your glucose down, over-reacting and driving numbers down too far. So in that case, high blood sugars wouldn't be a matter of diabetes, but one of delayed insulin. It's not just the numbers that decide whether someone is diabetic, it's what causes them that matters as well. That said, some people peak after eating some birthday cake for instance, and have absolutely normal blood glucose the rest of the time, because their metabolism can deal with it swiftly and accurately. So the numbers are not rock hard absolutes, circumstances, causes, they do matter.

...And sometimes I really should just take time to see what other responses there have been, because @Melgar was a lot more scientific and thorough than I was! Ah well.

 

[Chris24Main]

I guess I should chip in with my usual "but - insulin resistance" chime...

@daski - it looks like you are already well ahead of the curve in terms of pulling in and figuring out some of the terms. In trying to get a grip on what any given level of glucose measurement means, you should be aware that while all the focus is on glucose, because it's much easier to measure, therefore all the diagnostic thresholds are based on it... T2 is all about the insulin. This can often be about some kind of impairment to the pancreas (not just pancreatitis) but is often wrapped up in the topic of insulin resistance.

At its most simple - your body produces insulin as a response to high blood glucose, which acts to pull the glucose out of the blood, though as a hormone, it's hugely influential all over your body and does many other things. Over time, if you repeatedly ask for lots of insulin, your body will require more in order to have the same effect - like becoming less sensitive to any kind of stimulus, even coffee. So, for a long time, measured in decades... your blood glucose can stay relatively normal because you're able to keep producing even more insulin.

This twin effect of having too much circulating insulin and at the same time, not being able to use it as well as you might like (for example in your brain, causing brain fog, because the brain cells can be surrounded by glucose and not know what to do with it, because they are "blind" to the insulin) is called insulin resistance.

It's much more difficult to measure, so we typically rely on measuring blood glucose; but that only starts to become a thing when our body struggles to keep up with the curve.

The good news is that all the successful strategies around lowering blood glucose also lower circulating insulin.

 

[KennyA]

Thanks @KennyA , mine is 36. This article looks good, I will have a read.
I assumed that plasma glucose test is one that is done when your blood is taken (quite surprised you haven't had one as this is most default one I think that GP's use). Description states this:
A fasting plasma glucose test, also known as a fasting glucose test (FGT), is a test that can be used to help diagnose diabetes.
Furhermore as far I understand it is usually higher than capillary or CGM - meaning that result from plasma would be even higher than the one you have on CGM graphs or standard finger one.

Update after reading the article:
1. None of graphs go more than 180mg/dl
2. Percentage of time spent in different glucose ranges 140-168 max range
So now comparing to my level indicated by Libre and finger test of 14.0 mmol/L = 252.25 mg/dL so hm... rather not in any healthy range - plasma glucose would be even higher (5-15% more as far I could find).

Hi

No, plasma glucose tests (random or fasted) are not common at all and are certainly not the default test. In the UK almost all T2 diagnosis is done by an HbA1c test, which is the one everything is pegged around for diagnosis, payments, etc. You would not be diagnosed as t2 based on your (normal) HbA1c score.

It's also possible for tests to be simply wrong. For example, the acceptable accuracy for a fingerprick test is plus or minus 15%, for 95% of the time. So a true BG value of say 6.0mmol/l could return readings of anything between 5.1 and 6.9 and that would be OK. And one in twenty results could be well outside that, and that would be acceptable too.

Your BG (anyone's BG) at any given point will depend on a number of factors. Food is one, and probably by far the most influential. I tend to agree with your doctor - it's not possible to say definitely that a single recorded value of over 11mmol/l is definitely indicative of diabetes. If it was the case that you have chronically elevated blood glucose, you would expect to see that in your HbA1c result as well.

The diagnostic criteria for random plasma glucose are "A casual (random) plasma glucose level [equal to or greater than] 11.1 mmol/l in someone with typical symptoms of diabetes" and "A fasting plasma glucose level of [equal to or greater than] 7.0mmol/l" and "A plasma glucose level [equal to or greater than] 11.1 mmol/l two hours after a 75g load of glucose given by mouth (the oral glucose tolerance test)".

If you've not actually had a plasma glucose test than using its values against what your fingerprick/libre shows is going to be misleading at best. The fingerprick test uses capillary blood. The Libre tests using interstitial fluid. I'm definitely not saying that there isn't something you need to get to the bottom of, but arriving at a particular conclusion based on what you seem to be saying is a single high reading might be a bit premature.

 

[daski]

@KennyA thanks, let me address few things.
Following my Libre graphs I had not single high reading but exactly 13 of them in 14 days - so this is not a single event, furthermore for some of them I did as well finger check to make sure it is not Libre giving wrong data. MARD of Libre 3 is about 8%. I know it is an average so nothing very precise but you could say +-8%. So if you have readings of 13mmol/L this would be between 11. 96 or 14 (still too high).

On HbA1c - this measures average, I know now that diabetes is about sustained high glucose levels – so it is not my case as they go back to normal quickly. Saying all that in practice it doesn't really matter as despite having in range HbA1c you could still end up with coma or organ failures from high or low glucose (at least that is my understanding).

Now back to professional investigation. I sent Libre data and all results to specialist and had consultation online - then was told that:
1. these high readings are not normal (confirms what I thought)
2. they don't indicate diabetes (back to sustained factor) - but indicate resistance to insulin (issue 1) and reactive hypoglycemia (issue 2 probably as consequence of issue 1)
3. I have list of actions (usual exercise, diet and if no improvement medicine to avoid elevated glucose levels)
4. I have another appointment booked through BUPA with endocrinologist and some tests so should have everything re-confirmed

The only complain I have is that GP stating that these readings are ok and there is nothing wrong as my HbA1c is ok - is quite hm... far from anything I would consider a professional advice.
Thanks for all replies - they were really helpful.