Prediabetes I don't understand...A1C and FBG do NOT match

[CanadianGuy]

I am Canadians so I apologize if I am using units of measurement that are different from what this forum uses.

My doctor sends me for blood every 6 months when I renew my meds.

In late 2017, I was overweight and I was content with it. When I went to see my doctor, I spied on my last blood test that my fasting gluocse was 6.0 or 108, this test was a few months old. I asked him about it and he grilled me to lose weight.

I, of course, thinking I was in good health, FREAKED OUT and my anxiety went into overdrive. Every day I woke up scared of what potentially could happen. I worked out like crazy. But I worried. And he sent me for more blood. So a month of working out, losing weight, but still sweating buckets, and terrified to go back to get my blood test results. I am a very nervous blood test taker. I cannot for the life of me relax. So I went in there, sweaty and nervous. I took the blood test for my fasting and A1C.

I went back to my doctor....the FBG was now 6.4 or 115. But my A1C was 5.0.

I kept working out like crazy and my next FBG test was 5.7 (103) and my A1C was 5.1.

Then my next test after still adopting my new weight and healthy lifestyle, my FBG was 6.2 and my A1C went back to 5.0.

I am really disappointed that my FBG goes high like that. But I am confused that when I was fat and when I was a healthier weight and healthier diet made no real difference in my A1C. And despite keeping up a good lifestyle, my FBG goes higher again.

So why don't my A1C and my FBG match?
I offer this possible explanation...I hate going to the doctor, I hate medical tests, I hate hospitals, i hate feeling sick, I hate needles, and I am very nervous when I go.

Is it possible that's skewing the results?

I mean, despite my FBG going up and down but always being a bit higher than normal...my A1C stays pretty constant! In fact, me losing weight and eating healthier seemed to have no impact on A1C. If anything, it went up .1 lol.

What gives?

I am confused why my A1C and FBG don't match..one is "excellent" and one is out of normal range...

 

[Resurgam]

Why do you expect a single blood tests to match up with the Hba1c indication?
Why do you expect your wight to be significant? I realize that your dr told you that losing weight was a good idea, but I'd have thought that the main thing would be to lower your blood glucose levels - when all said and done, diabetes is all about the inability to deal with carbohydrates, so if nothing is being done to address that problem, very little will change.

 

[Tophat1900]

A1c is an average based on bg levels over a 3 month period. FBG is just what your bg level is right when you took it as soon as you wake up and it will change throughout the day. Your A1c is good.

Perhaps you can describe what you eat for meals? This is very relevant.

 

[VashtiB]

Hi

I agree with Resurgam. While the medical profession may worry about your weight- the first priority is your blood sugar levels. I have found that going low carb (very low carb in my case) has brought my blood sugar levels to within the normal range- including my HbA1c. It has also had the side effect of me losing weight- about 18 kilos in less than 6b months. I have done nothing for this weight loss. My focus has been on blood sugar levels- I have eaten plenty of cheese and cream and still lost weight. When my weight loss stalls as I expect it to I will reduce the amount of fat in my diet and may also lose the alcohol for a while- not that I drink very much anymore anyway.

I did this by low carb. My promise to myself is to focus on the blood sugars for at least 6 months before worrying about weight loss- I'm only human can't stress too much about everything. As a result I've lost weight anyway.

There is a saying that you can't outrun a bad diet- basically while exercise helps you need to have the right diet.

There is a difference between your blood sugar levels as measured by your meter and your HbA1C- read around on this site- I don't have a link sorry.

By the way- I heartily agree I hate going to doctors, hate needles etc- I'm sure my blood pressure at the doctors is higher than any other day- I think this is called white coat effect. You are certainly not alone- I will do almost anything to avoid any medical professional.

Another thing just to be aware of- while going low carb will help your blood sugar levels- stress will not- stress can make my readings much higher. Exercise also has an effect on blood sugars- if you do it before eating it may raise your blood sugar levels.

Do you have a meter and use it to test regularly? If you do and use the mySugr app it gives an estimate of you HbA1c.

The fasting blood sugar levels is often the last to drop- google dawn phenomena.

Good luck.

 

[CanadianGuy]

Thank you all for your replies. Admittedly, I eat some carbs still including cereals in the AM. I try and substitute "better" carbs e.g black rice for sushi, etc. and avoid potatoes and bread where possible.

A good solid meal for dinner for me is broccoli and a chicken breast...but I have unfortunately been known to feast on a NY style bagel. I know I need to cut the carbs outta there.
I find myself quite lethargic without them though, which makes it really difficult!

I have my own meter. If I get a good sleep, my blood sugar is 9/10 times less than 100 in the morning. Sometimes it'll go to maybe 105. I haven't tested for a while as I ran out of the strips. I was testing way too often, as in several times a day, and it was stressing me out more than it was helping.

 

[JoKalsbeek]

Thank you all for your replies. Admittedly, I eat some carbs still including cereals in the AM. I try and substitute "better" carbs e.g black rice for sushi, etc. and avoid potatoes and bread where possible.

A good solid meal for dinner for me is broccoli and a chicken breast...but I have unfortunately been known to feast on a NY style bagel. I know I need to cut the carbs outta there.
I find myself quite lethargic without them though, which makes it really difficult!

I have my own meter. If I get a good sleep, my blood sugar is 9/10 times less than 100 in the morning. Sometimes it'll go to maybe 105. I haven't tested for a while as I ran out of the strips. I was testing way too often, as in several times a day, and it was stressing me out more than it was helping.

Lethargic when you don't eat carbs? Probably because your body demands them, as they are highly addictive. Stick with it for two weeks, and you'll have all the energy in the world. Take it from someone who was so fatigued she couldn't get out of bed anymore. https://josekalsbeek.blogspot.com/2019/11/the-nutritional-thingy.html <-- this might help too.

Step away from the rice and bagels though. (And discover the joys of cauliflower rice. That stuff's amazing).

 

[mouseee]

Sounds like stress is playing a big part.
Your numbers aren't really very high. Various websites give the normal range as being between 4 and 7. Morning bs can be affected by the liver dumping glucose.

Everyone's blood sugar varies during the day. And when you test it's a bit like looking out if the window to see what the weather's like at that moment. The Hba1c looks at the weather over the past 3 months and tells you what the weather patterns were.

Well done on making a healthy lifestyle choice. Just keep that going and you'll see changes.

 

[Marie 2]

You said
I kept working out like crazy and my next FBG test was 5.7 (103) and my A1C was 5.1.

103 Bg level equates to 5.2 A1C so it coming in at 5.1 is accurate because there can be a variance in lab testing too.

Preferably FBG are usually under 105, but it can vary and stress can even send it up a little. The 108 and 115 FBG might have been a warning about what was going on, but you lost weight started exercising, both really healthy things to do. And a .1 variance doesn't mean anything, there is a level of wiggle room in testing because different labs and the exact same blood samples can vary some at the same lab.

You seem to be doing great now, just keep an eye on it off and on.

Normal A1C levels for non diabetics etc
https://www.diabetes.org/a1c

Here is a chart of Bg levels and what it equals to A1C level
http://coping.us/images/A1C_to_Blood_Glucose_Conversion_table.pdf

 

[ziggy_w]

Hi @CanadianGuy,

As @Marie 2 says, your HbA1cs are absolutely normal and a 0.1% difference could just be measurement error.

Possibly the higher fasting levels are due to stress. Do you have a blood glucose meter? If yes, try to measure fasting levels if you are not stressed and see if it makes a difference.

 

[Daibell]

Hi and welcome. Your numbers are very good so stop worrying (my HBa1C was 12% when diagnosed!). Yes, diet is more important then exercise although the latter is always good. Do keep the weight within a good range otherwise you can end up with insulin resistance etc. Do try to avoid stress as that is never good and will push blood sugar up. Keep the carbs under control and currently you should be fine. BTW the FBG is never a particularly useful test as the overnight liver dump can influence it. The HBa1C is normally very reliable and tests with a glucose meter 2 hours after a meal can be useful.