Fasting bg tests

jumbleannie1VDJQ

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Can anyone explain to me what is the significance of the fasting tests please.
Mine do not seem to make any sense, as I usually try to make sure mine bg levels are below 8 at bedtime and my average on waking is 6.2. Last night after a heavy day at work, (I decided to clear out the attic, which meant shifting a lot of boxes of books and bags), I was too tired to care that my levels were running at 10 so I just zonked out. This morning I expected the worse, but have just got a reading of 5.3. Why? No abnormal amount of alcohol, and I had paella for supper, a rare occurence, but since hubby was cooking I wasn't about to turn it down. :lol:
Everyone, from the doctor to this forums members seem to be obsessed with fasting tests, so does anyone else have these weird readings?
I'm borderline diabetic, on no medication and with a hba1c of 6.5.
 

Grazer

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People like to take them to get a general idea of how they are doing, to see if there are any big changes. Personally, I don't find them much use. There are too many anomalies. If you have dawn phenomenon (small liver dump before you wake) it will be significantly higher than if you don't. If you take it as soon as you wake, it will be different for most people to if you take it after a shower etc, even if you still haven't eaten. Occasional checks to see if anything alarming is happening is ok I guess. I test more after to food to see how I react to different food types cooked in different ways and eaten at different times of day etc. That way I can change what I do accordingly to get desired BGs. Testing fasting BGs did show that I got worse readings if I had food too close to bedtime, so I don't do that now. Other than that, I can't do much to change my fasting BG so don't bother testing other than now and again for curiosity!
 

viviennem

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This is a very interesting question. I admit that I take mine in a morning as a sort-of reminder that I have Type 2 diabetes and need to act accordingly. It's now part of my routine, and only very occasionally do I miss it. It sets me up for the day, and it also indicates anything out of the ordinary. Like Grazer, I don't do much other testing these days - and the less said about Christmas, the better! :oops:

I'm sure testing before and 2 hours after a meal would give me a better indication of what's going on.

Regarding ordinary fasting tests at the GP - these must invariably include a liver dump, even if a very small one, so I don't really see what use they are - they are not a true picture. I live about 5 minutes from the surgery, but even if I'm first in with the nurse, I will have been up and about for at least an hour. And what's the point of giving a fasting blood test if your appointment isn't until 10 am? That's a genuine question, by the way.

I once did a test with my own meter at exactly the same time as the nurse was taking the samples for the lab. My meter - 5.4. Lab test result - 7. :?:

Viv 8)
 

Daibell

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I discussed fasting tests with another long-term Type 2 at an NHS diabetes group meeting recently and we both agreed the overnight BS fasting test shouldn't be relied upon too much due to liver dumps. The before and 2 hours after a typical meal is a much better approach to meter testing.
 

Grazer

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Hi Viv, not sure why you're giving fasting BGs at the surgery? A couple of high ones in a row are used to give a preliminary diagnosis, but AFTER you're diagnosed I can't see why they want it? By the way, your simultaneous meter/lab reading isn't a timing issue. If you drew the blood at the same time, the BG analysis wouldn't change with time thereafter. It would be a meter accuracy issue.
 

borofergie

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Meter accuracy sucks don't it?
 

viviennem

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They do it automatically, Grazer, every 3 months when I have my HbA1c, lipids etc done. It comes back on the print-out.

Meter accuracy does suck - but I still don't understand! If my meter is reading 1.3mmol/l under the lab test results, how come after 3 months in the mid-5s by my meter - say 5.5 for the sake of argument, which would be 6.8 according to the lab - the same lab can give me an HbA1c of 5.2?

I'm now treating my meter pretty much as I do my bathroom scales - they may not be accurate, but at least they're consistent and show up or down! I'm sure each new pot of test strips can differ a little, too.

Don't let my quibbles put anyone off testing - accurate or not, my control would be very much worse if I didn't have a meter! My fasting test these days is routine and doesn't mean much, but I still do the full 8 tests per day every now and again to make sure everything is okay.

Viv 8)
 

Unbeliever

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Totally agree with you Viv. That is exactly the point [but re home bp monitoring} I am ryig o get over to the diabetic nurse.

Self -testing of any kind is so that you can keep track of things for yourself . To quibble about 100%
accuracy is to miss the point. If something looks wrong or inconsisent then is the ime o look into it.

We are not trying o compete with professional equipmen etc merely o keep an eye on our own conditions so that any problems are picked up sooner.

I find that just a few days without testing my bg can resul in higher readings because I have not had the opportunity to adjust any blips.
 

Grazer

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viviennem said:
but I still don't understand! If my meter is reading 1.3mmol/l under the lab test results, how come after 3 months in the mid-5s by my meter - say 5.5 for the sake of argument, which would be 6.8 according to the lab - the same lab can give me an HbA1c of 5.2?

Remember Viv, an HbA1c of 5.2 (Lucky girl! Well done!) equates to an average blood glucose (in the units measured by your meter) of 6.0, so not far off your meter. ALSO, the HbA1c refers to the OVERALL average; even if you take 8 readings every day, you don't know what's happening in between. In fact, if you measure 2 hour post prandials, your BG after that would be lower, so you'd expect your overall average to be lower than the average of your meter readings.
 

smidge

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Hi Viv,

We've had a similar discussion recently on one of the other boards about how the meter readings relate to the HbA1c - the conclusion was they don't really (I think!). Anyway, here's the link (not sure if the link will work but I'll try):

viewtopic.php?f=15&t=25932

Smidge
 

viviennem

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Thanks, Grazer and Smidge, and thanks also for the PM, Grazer. You've cleared it up nicely :D .

Anyway, as with everything else in my life (particularly weighing scales :lol: ), if my own meter says I'm lower than the lab on a fasting test, I believe my meter :wink:

One of my GPs lives in the same village and has walked past my house twice today; another lives about a mile away and has just ridden past on his horse. I'm beginning to think I'm under surveillance! At least I was doing a bit of gardening - 1.5 hours today, just a bit of tidying and lawn edging. Exercise :shock:

Viv 8)
 

jumbleannie1VDJQ

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Thanx all, will forget the morning test and go for the before and after dinner test instead I think. Still can't work out why the low result after paella though. Oh well!!!
 

viviennem

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You maybe frightened your pancreas into a burst of activity :lol: . The lowest reading I've ever had was 3.6, 2 hours after a lunch of cheese sandwich and a 99 icecream. :shock:

I'm going to test around my main meal too, at least for a few days while I get back in control.

Viv 8)