Fasting Blood Glucose Test

[Listlad]

What does this test tell us?

I am due for one this week (late booking owing to poor coordination between us all at my surgery).

 

[edan]

It tells you your fasting blood sugar level. It’s used to diagnose diabetes.

 

[EllieM]

It tells you your fasting blood sugar level. It’s used to diagnose diabetes.

And it's not very useful (just my opinion). I would have thought an hba1c or a glucose tolerance test would be far more informative.

 

[Listlad]

And it's not very useful (just my opinion). I would have thought an hba1c or a glucose tolerance test would be far more informative.

I see. I had the HbA1c at the end of February.

 

[Deleted member 308541]

What does this test tell us?

If it's the one I am thinking of for a fasting glucose test, they take a sample of blood from your arm. Then they get you to glug a small bottle of glucose drink down. After a period of time another blood draw is done, then after another hour another blood draw is done.

I was at the pathology shop for a couple of hours every time I had them done, it's been a while now though. I get to see people getting them done when I go for blood tests, they always seat you near the toilets in the waiting room just in case you throw up..

 

[EllieM]

And it's not very useful (just my opinion). I would have thought an hba1c or a glucose tolerance test would be far more informative.

Just seen that Feb's hba1c is 36. I can't honestly see what the point of a fasting blood sugar is in that case, unless they actually mean a glucose tolerance test? Or don't believe the hba1c for some reason? Could just be surgery incompetence?

 

[Listlad]

If it's the one I am thinking of for a fasting glucose test, they take a sample of blood from your arm. Then they get you to glug a small bottle of glucose drink down. After a period of time another blood draw is done, then after another hour another blood draw is done.

I was at the pathology shop for a couple of hours every time I had them done, it's been a while now though. I get to see people getting them done when I go for blood tests, they always seat you near the toilets in the waiting room just in case you throw up..

Nice one.

I had one done last year. There were a heap of checks done from the same sample after fasting overnight. My last one in Feb 2018 was designated abnormal and in the diabetic range - 6.8 mmol/l

 

[Listlad]

Just seen that Feb's hba1c is 36. I can't honestly see what the point of a fasting blood sugar is in that case, unless they actually mean a glucose tolerance test? Or don't believe the hba1c for some reason? Could just be surgery incompetence?

What it is, is that they were all supposed to have been done at or around the same time. At the time I didn’t know that. Once I realised I should have had the other tests done around the same time I asked them to do those that hadn’t been done. Hence the delay.

 

[Deleted member 308541]

Here's what is on the bottom of a hba1c report from the pathology shop that may be of use / interest to you

 

[Listlad]

Just looked this up:

Fasting blood glucose level

• If your blood glucose level is 70 to 99* mg/dL (3.9 to 5.5 mmol/L). . .
  • What it means: Your glucose level is within the normal range
• If your blood glucose level is 100 to 125 mg/dL (5.6 to 6.9 mmol/L). . .
  • What it means: You have an impaired fasting glucose level (pre-diabetes**) . . .
• If your blood glucose level is 126 mg/dl (7.0 mmol/L ) or higher on more than one testing occasion
  • What it means: You have diabetes

 

[Listlad]

My test result yesterday was 6.0 so that puts me in the Prediabetes range.

The surgery records have it as within the normal range however.

 

[Oldvatr]

Just looked this up:

Fasting blood glucose level

• If your blood glucose level is 70 to 99* mg/dL (3.9 to 5.5 mmol/L). . .
  • What it means: Your glucose level is within the normal range
• If your blood glucose level is 100 to 125 mg/dL (5.6 to 6.9 mmol/L). . .
  • What it means: You have an impaired fasting glucose level (pre-diabetes**) . . .
• If your blood glucose level is 126 mg/dl (7.0 mmol/L ) or higher on more than one testing occasion
  • What it means: You have diabetes

A fasting blood test is also normally done when testing for cholesterol levels in the blood, simply because cholesterol is significantly changed after a recent meal and results will be inconclusive,

 

[bulkbiker]

Just think ... if you bought your own meter you could get this number every morning and check whether its up or down..

 

[Listlad]

Just think ... if you bought your own meter you could get this number every morning and check whether its up or down..

I haven’t ruled that out. I just put the idea on the back burner.

 

[Bluetit1802]

I have to agree with some of the others. Once diagnosed, there is no point in further fasting blood glucose tests. They tell you very little. The best way forward is to buy a meter and test your own, keep records, and watch for trends. They are unreliable, particularly ones done in the surgery because by the time the test is taken other factors have come in play, such as anxiety of the test itself, rushing about before the test, and so on. All these things change our blood sugar levels.

The main thing testing at home teaches us is the state of our insulin resistance. The more IR we have, the higher our fasting BG is likely to be, and the longer it takes to reach normal levels again.

 

[Listlad]

So, my medical record has me as prediabetic, my FBG has me in the prediabetic range. My HbA1c has me in the normal range. So reading between the lines I am still Prediabetic.

 

[Mr_Pot]

I see. I had the HbA1c at the end of February.

As someone who is pre-diabetic at worse you seem to be getting a lot more attention and testing than some on here who have high HbA1c and are definitely diabetic. Is there some special reason why you are getting this ideal but unusual treatment?

 

[Tophat1900]

I haven’t ruled that out. I just put the idea on the back burner.

FBG levels can bounce around, you could record a trend if you had a meter and see if it trends up or down over time. Rather then just having a once a year level done, which gives you no real worth while info due to the many variable reasons for why a level is higher or lower on just one particular day. That's if that sort of thing interests you.

 

[Tophat1900]

So, my medical record has me as prediabetic, my FBG has me in the prediabetic range. My HbA1c has me in the normal range. So reading between the lines I am still Prediabetic.

Your fasting blood glucose level does not trump your hba1c level. And that is good news. I wouldn't say you are pre-diabetic, unless I'm missing something?

 

[Listlad]

As someone who is pre-diabetic at worse you seem to be getting a lot more attention and testing than some on here who have high HbA1c and are definitely diabetic. Is there some special reason why you are getting this ideal but unusual treatment?

That is a very good question. And the answer is not straight forward. This might help explain:

1] For 7 years I was in the care of the Isle of Man NHS. They were a bit more proactive with my care even if they didn’t advise LCHF. I got used to asking which was almost always responded to positively. I brought that expectation back with me to the UK in 2017.

2] This latest test should have been carried out when I had my HbA1c test done in late February. This was because I didn’t ask (ignorance on my part) and they didn’t arrange it proactively. I had to ask for the HbA1c test and the FBG test. If I hadn’t asked then I would be nonethewiser now.

3] In general I do ask (nicely) and find it helps. I cherry pick the best GP for me where I can. That helps too.

4] My GP is very LCHF freindly as explained before. That helps.

5] I am also registered with hypertension so that is likely to be another factor.

All or some of the above are likely to be factors.