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Blood tests 1 week before and after comparison, confusing due to the fasting glucose?

L

lilywonder

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Hi everyone,

I am asking this for my brother who is a little worried about his results. He is a power lifter and a heavy person. 34 yo, 6.2 280 lbs muscular man.

Lately he had been following intermittent fasting regime and felt a little tired after his first meal breaking the fast which got better gradually.

Our family doctor ordered some routine blood work for him.

One week ago his results for hbA1C without fasting showed 5.5% and glucose random showed 5.4. In Canada, apparently if it is above 5.5 it is considered prediabetics. (not sure about fasting glucose)
So he sent him again for another blood test this time, fasting and hbA1c to compare.

His fasting glucose came to 5.9% after 16 hours of fasting. He ate around 11 PM after gym, and went for the test next day around 3 PM in the afternoon. We dont know if fasting for that long increased the glucose level.

I have included the screenshots of both the test results, 1 week before and after for comparison.

Please advise. Our family my mothers side has diabetes in the family but our fathers side no diabetes genetically.

What should we test next, I wonder if OGTT is necessary for him. I am worried if he gets it, if I would get it too and start
monitoring it, the carbs.


This is as of today.






Following is 1 week before.



I also thought fasting blood sugar is the one that would be normally low compared to the random glucose test because one has not eaten anything for so long so there wont be any spike. It is surprising to see it is higher after fasting for 16 hours.

Please share your thoughts.
 
So he ate a meal at 11pm post workout the night before and after a 16hr fast, at around 3pm he then did the test.

To be honest I would not of done a fasting test or any blood test under those conditions.

Glucose levels will fluctuate - he would still be in recovery mode which will play a roll in his level. The difference between 5.4 and 5.9 is really just marginal. So many factors will influence it from the workout to sleep quality and fasting. I wouldn't be surprised if he ate something to break the fast and it dropped. Unless he ate a lot of starchy foods.

Personally, I think the second result is pretty close to worthless. It would be better to do the test in the morning after an uneventfull previous night, before you are up and really mobile for the day.
 

There are many reasons why a fasting glucose number isn't routinely used to diagnose T2 diabetes. Many things can influence a single reading, like stress, lack of sleep, what was eaten before the fasting period.

I am completely unfamiliar with diagnostic protocols in Canada, but in UK, there would be more focus on the HbA1c reading, as that indicates longer term control, and includes any peaks or troughs experienced.
 

According the results posted it has the ref range for Hba1c and they seem to be the same as UK?

5.5 means you are just entering an at risk range, but not prediabetic till reaching 6%
 
Tophat1900 said:
According the results posted it has the ref range for Hba1c and they seem to be the same as UK?

5.5 means you are just entering an at risk range, but not prediabetic till reaching 6%
Click to expand...

I have no push back on that, as a number on the page, but fasting glucose is a frail measure - especially I would wager at 3pm. I know my liver would have been making generous contributions by then to my blood glucose numbers, irrespective of a long fast.

@lilywonder was exhibiting great focus on the fasting reading, rather than the A1c, which is where most UK diagnoses come from, for T2. T1s and gestational differ.
 
Helly Tophat1900,

Thank you so much for responding very clearly enough for someone who is new to this can understand it. I really appreciate it.

Based on your response, my brother is not doing good at all.
So he spent around 2 to 2 and a half hours in the gym last night, and ate a very large meal after he got home around 11 PM. He only got appointment around 3 PM. I dont think he slept that well either. He just got divorced 10 year old marriage and for the past 1 year he has been getting more and more intense into the weight lifting, too much that is, following some kind of a self help author. So that is why we are trying to look after his well being since he moved back shortly after divorce.

If weight lifting and not sleeping can cause that fluctuation what would you suggest please. His hbA1c went down to 5.4 from 5.5 a week ago. How would that be possible if hbA1c looks at the stored sugar for the past 3 months. Shouldn't it be more in the recent test.

If this is all too much of information, can you please suggest what he needs to do now, more importantly what do I need to do, to never become diabetic, since it is in our family from our mom's side. I am already on low carb, my brother says he can never do low carb because of his weight lifting habits.

Should we ask our doctor to get OGTT and another hbA1c in a couple of months?

Also I am not sure about the test reference range for UK vs Canada. But I do know that USA tells if it is above 5.6 you are prediabetic. But Canada says, 6.0 and above. I dont know why they have a larger number, possibly because Canada has free health care and dont want more patients? I will trust UK when it comes to anything medical related.





 

In general is, hbA1c considered more accurate or reliable than the fasting glucose level? Is fasting glucose unreliable?

I am very confused because why don't we have any one reliable tool to diagnose it. I was under the impression that OGTT > hbA1c > Fasting glucose?

Edit: Sorry I just missed your earlier post. We will get another test in a couple of months to check his hbA1c and see if it is okay. Thank you.
 
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I don't think he is doing badly at all, I just highlighted that doing a fasting at 3pm after all he'd done the late night before just isn't a good time to do that test. It can throw the numbers off on all kinds of tests temporarily. And the hba1c is of more interest. It is a more reliable test than fasting blood glucose. If it stays below 5.5 he is going ok, if it were to trend upwards over time that would imo be a sign something needs to change and that is usually diet that needs a rethink. I don't think for one minute he is diabetic. You could ask for another hba1c in a few months, I don't see any reason for ogtt, but if you're curious you could.

Weight lifting is great, it's the immense amount of starchy carbs that is imo a problem, but what he eats is up to him.

I'm not sure why you are concerned if you are doing low carb? That's pretty much the right way to go about avoiding T2
 

I am a bit concerned because I am doing low carb and every 2 weeks or so, I have a cheat day and I eat a lot of carbs for one day. This website and community is amazing with a lot of information and helpful people. Thank you very much, I will post back if we had any other questions and help.
 
lilywonder said:
His hbA1c went down to 5.4 from 5.5 a week ago.
Click to expand...
Lab tests have a margin of error. With HbA1c, 5.4% and 5.5% are essentially the same number. So, your brother's HbA1c has been confirmed as being below the pre-diabetic range.
 
lilywonder said:
Please advise.
Click to expand...

Welcome to the forum. There's a couple of tests that your brother can have done that might help form a more complete picture. One is a c-peptide test which will let you know how the pancreas is doing and then there is an insulin resistance test. More importantly, a doctor is the best (only) person to give any advice.
 
As said above, the two HbA1c tests are virtually identical. There is no significant difference between them.

The random blood glucose test can be ignored completely. It was not fasting and for all anyone knows he could have eaten a meal or snack or a drink fairly close to the test. In the UK a random blood glucose test has to be over 11mmol/l.

Here in the UK it is quite rare these days to diagnose type 2 diabetes or prediabetes with a blood glucose test. The HbA1c is always used, or sometimes the OGTT although this is normally only given to pregnant women as the HbA1c is not suitable for them. In cases of type 1 diabetes it is a different matter, and I am no expert on this.
 
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