HbA1c and home testing

[BernieRoss]

Hi. Sorry if this is a stupid question - I'm new to this.

On being told I had pre-diabetes, I bought a monitor and my average reading (taken at random times) was between 5.5 and 6.00, which as I understand it is perfectly OK. But my latest HbA1c result is 47, which I'm told is right at the edge of T2. For the past ten days I've cut my carb and sugar intake down massively, but when I test my blood now, there's no discernable difference in blood sugar levels. I know I have to wait 3 months for the next HbA1c test, but I can't understand how that result can be high, and my home test results are continually OK. I'm pretty sure I'm not missing any spikes in levels, because I've taken dozens and dozens of readings, but never seem to get a high one. Very grateful indeed if someone could explain what might be going on!

 

[HSSS]

Hi. Sorry if this is a stupid question - I'm new to this.

On being told I had pre-diabetes, I bought a monitor and my average reading (taken at random times) was between 5.5 and 6.00, which as I understand it is perfectly OK. But my latest HbA1c result is 47, which I'm told is right at the edge of T2. For the past ten days I've cut my carb and sugar intake down massively, but when I test my blood now, there's no discernable difference in blood sugar levels. I know I have to wait 3 months for the next HbA1c test, but I can't understand how that result can be high, and my home test results are continually OK. I'm pretty sure I'm not missing any spikes in levels, because I've taken dozens and dozens of readings, but never seem to get a high one. Very grateful indeed if someone could explain what might be going on!

It’s all about when you test. And if you miss lots of highs and or lows you’ll get misleading averages.

Typical type 2 (which is where unchecked prediabetes might lead) patterns would show higher fasting morning numbers. Then likely a steady drop til food eaten. Depending on what food a rise peaking somewhere often about an hour or so later and then dropping back down ideally coming fairly close to the permeable reading after a couple of hours or so. Rinse and repeat. Illness, sleep, exercise, stress all also have effects.

The key factor is the food though most of the time. Some foods shoot it up high and fast, others a more steady and longer rise but not so high and still others barely touch it. Carbohydrates will do the most damage (not just sugar, all carbs of all colours), protein might do a small amount and fats none to speak of. Combinations of foods will effect peaks and duration too.
So cutting the carbs is good. If you want a good baseline testing on waking, before and 2hrs after each meal for a while. Ideally the post prandial rise should be no more than 2mmol or even better less. This shows it was a meal you coped with. More and there were too many carbs for you. As well as identifying problem foods you’re looking for trends to see overall improving averages.

Getting few high readings is good if done at the right times . It shows your changes are working and hb1ac will be falling.

 

[searley]

As an example for you.. based on me doing 5 tests a day downloading the results to an app and it working out what my hba1c estimate is. It estimates an hba1c of 57

In reality my hba1c was 76 The reason it’s so far out is it’s only taking the results from those 5 points in the day it’s not seeing that my blood sugars are 10+ all night long or that my bg’s are rising high from about 4am. Or that in the hour after my meals I can rise to over 20

When I put on a constant glucose monitor I can see all that and the estimate is more accurate

With any luck your next hba1c will come back at a lower level

 

[BernieRoss]

Many thanks to both of you! But it really is odd that not one of the tests I've done (there have been very many indeed) has hit one of the high spikes. I haven't woken at 3.00 a.m. and tested myself in the middle of the night. I guess I should. Another thing has been that I've had high stress levels for the past year or so, and have been working at home, not eating regular meals but just snacking (largely on bread!) throughout the day. All the info and instructions as to when to test (eg. "two hours after a meal", or "just before eating", etc) don't work for a bloke like me that just tends (well, tended - I've stopped now) to snack very often, and eat proper meals only occasionally. Heroic levels of tea and coffee consumption (with sugar) didn't help either! I'll keep testing, and wait for the next HbA1c, which I guess is the real measure I should be paying attention to. But it seems that the bg tests that I've done, were pretty useless as an indication of how I'm doing.

 

[HSSS]

Many thanks to both of you! But it really is odd that not one of the tests I've done (there have been very many indeed) has hit one of the high spikes. I haven't woken at 3.00 a.m. and tested myself in the middle of the night. I guess I should. Another thing has been that I've had high stress levels for the past year or so, and have been working at home, not eating regular meals but just snacking (largely on bread!) throughout the day. All the info and instructions as to when to test (eg. "two hours after a meal", or "just before eating", etc) don't work for a bloke like me that just tends (well, tended - I've stopped now) to snack very often, and eat proper meals only occasionally. Heroic levels of tea and coffee consumption (with sugar) didn't help either! I'll keep testing, and wait for the next HbA1c, which I guess is the real measure I should be paying attention to. But it seems that the bg tests that I've done, were pretty useless as an indication of how I'm doing.

Well cutting the sugar and bread is the right direction. Hb1ac and bgl measure different things and give you different things. Hb1ac as an average won’t tell you which foods are wrong. It can be lots of really high numbers and some really low ones neither of which are great (admittedly more an issue for those on glucose lowering meds like insulin as most others are unlikely to go too low) or it can be a nice smooth line of stable levels. It won’t tell you how you’re going day to day and you have to wait months for a progress report. It is however a better overall picture than bgl. Do your best to stop the snacks and have filling meals instead (allowing for the +2hr from start of eating window). Each intake of food raises insulin and higher constant insulin levels contribute to the fundamental problem of insulin resistance that you are trying to overcome. It keeps you on the rollercoaster of carb addiction and cravings too.

 

[BernieRoss]

Thanks. Not missing carbs at all, but a bit of sugar in the first coffee of the day would be nice. But I can do without it. So far so good, but I would like to see some results!

 

[searley]

Thanks. Not missing carbs at all, but a bit of sugar in the first coffee of the day would be nice. But I can do without it. So far so good, but I would like to see some results!

Sugar in coffee I missed I now just have 1 sweetener got used to it after a week or so

I now notice if someone gives me a coffee with sugar in

 

[HSSS]

Thanks. Not missing carbs at all, but a bit of sugar in the first coffee of the day would be nice. But I can do without it. So far so good, but I would like to see some results!

Did you do any testing before changing what you eat? I only tested a after drastically changing diet. Sometimes wish I’d done it the other way round so I had something to compare to but not about to throw a load of carbs down my neck just to find out. The odd dodgy choice in limited amounts is enough on the meter to convince me not to do worse. Hate to think what it used to reach.

 

[EllieM]

I know I have to wait 3 months for the next HbA1c test, but I can't understand how that result can be high, and my home test results are continually OK.

Most likely you're just missing the highs (eg by not testing at night) but some people do have misleading (high or low) hba1c results due to a long list of various anomalous blood conditions (eg anaemia, sickel cell, .... even lead poisoning).

https://www.goodrx.com/blog/could-your-hba1c-diabetes-test-be-wrong/

If you think there is reason for a genuine discrepancy, you can ask for a fructosamine test instead.

 

[BernieRoss]

I started testing about a year ago when I got my first HbA1c result which showed 42, but as I got consistent good results on my home tests, I didn't really change my diet. About three weeks ago I got the result of a recent test which showed 47, and that's when I quit sugar and cut down on carbs. There is no apparant difference between the home readings after the HbA1c test a year ago, which showed 42, and since I started testing again three weeks ago, following the HbA1c result of 47. Since then, following three weeks of almost zero carbs, blood sugar tests are still the same. I do (still) tend to snack late at night, and sleep for an absolute max of 6.5 hours, usually only 5. First thing this morning, 6 hours after eating, I got a reading on 5.2 mmol/L. Two hours after an egg and bacon breakfast (no toast or carbs), I got 5.8. Same pattern as ever.

In short, there seems to be no relationship at all between my home test results, and the HbA1c test results. Also, so far, there seems to be no relationship between the home test results and my carb intake. Very confusing.

Did you do any testing before changing what you eat? I only tested a after drastically changing diet. Sometimes wish I’d done it the other way round so I had something to compare to but not about to throw a load of carbs down my neck just to find out. The odd dodgy choice in limited amounts is enough on the meter to convince me not to do worse. Hate to think what it used to reach.

 

[Daphne917]

Thanks. Not missing carbs at all, but a bit of sugar in the first coffee of the day would be nice. But I can do without it. So far so good, but I would like to see some results!

I still have 1/2 teaspoon of sugar on my strawberries

 

[BernieRoss]

Wow Daphne! Excellent results! I have also recently been prescribed a statin. Your mention of it prompted me to investigate the significance vis a vis diabetes, and I found a very interesting link (it seems I can't post the url here). I'll have a word with my doctor.

I still have 1/2 teaspoon of sugar on my strawberries

 

[Daphne917]

Wow Daphne! Excellent results! I have also recently been prescribed a statin. Your mention of it prompted me to investigate the significance vis a vis diabetes, and I found a very interesting link (it seems I can't post the url here). I'll have a word with my doctor.

Thanks! I came off the statins due to other side effects but my dr has now annotated my notes as statin intolerant because we don’t want to risk it happening again.