Why hemoglobin A1c is not a reliable marker

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Over the last few years doctors are increasingly relying on a test called hemoglobin A1c to screen for insulin resistance and diabetes. It’s more practical (and significantly cheaper) than post-meal glucose testing, and it’s less likely to be skewed by day-to-day changes than fasting blood glucose.

What is hemoglobin A1c?

Sugar has a tendency to stick to stuff. Anyone that has cooked with sugar can tell you that. In our bodies, sugar also sticks – especially to proteins. The theory behind the A1c test is that our red blood cells live an average of three months, so if we measure the amount of sugar stuck to these cells (which is what the hemoglobin A1c test does), it will give us an idea of how much sugar has been in the blood over the previous three months. The number reported in the A1c test result (i.e. 5.2) indicates the percentage of hemoglobin that has become glycated (stuck to sugar).

Why is hemoglobin A1c unreliable?

While this sounds good in theory, the reality is not so black and white. The main problem is that there is actually a wide variation in how long red blood cells survive in different people. This study, for example, shows that red blood cells live longer than average at normal blood sugars. Researchers found that the lifetime of hemoglobin cells of diabetics turned over in as few as 81 days, while they lived as long as 146 days in non-diabetics.

This proves that the assumption that everyone’s red blood cells live for three months is false, and that hemoglobin A1c can’t be relied upon as a blood sugar marker. In a person with normal blood sugar, hemoglobin will be around for a lot longer, which means it will accumulate more sugar. This will drive up the A1c test result – but it doesn’t mean that person had too much sugar in their blood. It just means their hemoglobin lived longer and thus accumulated more sugar. The result is that people with normal blood sugar often test with unexpectedly high A1c levels.

This confused me early in my practice. I was testing blood sugar in three different ways for all new patients: fasting blood glucose, post-meal blood sugar (with a glucometer) and A1c. And I was surprised to see people with completely normal fasting and post-meal blood sugars, and A1c levels of >5.4%.

In fact this is not abnormal, when we understand that people with normal blood sugar often have longer-lived red blood cells – which gives those cells time to accumulate more sugar.

On the other hand, if someone is diabetic, their red blood cells live shorter lives than non-diabetics. This means diabetics and those with high blood sugar will test with falsely low A1c levels. And we already know that fasting blood glucose is the least sensitive marker for predicting future diabetes and heart disease. This is a serious problem, because fasting blood glucose and hemoglobin A1c are almost always the only tests doctors run to screen for diabetes and blood sugar issues.

Another condition that affects hemoglobin A1c levels is anemia. People who are anemic have short-lived red blood cells, so like diabetics, they will test with falsely low A1c levels. In my practice, about 30-40% of my patients have some degree of anemia, so this is not an uncommon problem.

What blood sugar markers are reliable?

Testing accurately for blood sugar is like putting pieces of a puzzle together. Fasting blood glucose, A1c and post-meal blood sugar are all pieces of the puzzle. But post-meal blood glucose testing is by far the most reliable and accurate way to determine what’s happening with blood sugar, and the most sensitive way of predicting future diabetic complications and heart disease.

For more on why post-meal blood sugar is a superior marker, read my article When Your Normal Blood Sugar Isn’t Normal (Part 2). To learn how to test your post-meal blood sugars at home, and what healthy targets should be, read my article How to Prevent Diabetes and Heart Disease for $16.

Another useful – but underused – blood sugar marker is fructosamine. Fructosamine is a compound that results from a reaction between fructose and ammonia or an amine. Like A1c, it’s a measure of average blood sugar concentrations. But instead of measuring the previous 12 weeks like A1c, fructosamine measures the previous 2-3 weeks. And unlike A1c, fructosamine is not affected by the varying length of red blood cell lifespans in different individuals. Fructosamine is especially useful in people who are anemic, or during pregnancy, when hormonal changes cause greater short-term fluctuations in blood glucose levels.

To put the most accurate picture together, I like to have all four: fasting blood glucose, A1c, post-meal glucose and fructosamine. But if I only had to choose one, it would definitely be post-meal glucose.

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  1. says

    Hi Kris,

    Great article, I think this really clears up what has been going on with me.

    You might recall a couple months back- I was asking about why my A1c was 5.7 when I am full ancestral/paleo nutrition for over a year, lowish carb, 10% body fat, and a competitive athlete. HDL was over 100, triglycerides about 40, CRP less than .1 . My blood sugar levels never went over 120 even after meals and were usually around 86 fasting, but because of the 5.7 A1c my doctor said that I was close to prediabetic levels!

    It freaked me out to be honest, so I did a bunch of research and decided that I must just have long-lived RBCs. It’s good to hear that this is a fairly common occurrence, and this makes a lot more sense.

    Now I’m going to go listen to the Robb Wolf Podcast, I’m excited to hear it.

    Tyler

  2. qualia says

    last time my A1c was 5.2% – which is 4.8nmol according to my lab report – which is 86mg – which is pretty much my usual fasting level. so why would all the labs and docs still use A1c if it really was THAT unreliable (especially in pre-diabetics)? what would keep them from switching to fructosamines a long time ago, or at least routinely measure both (they’re both rather cheap)? i mean, 3 weeks of average sugar is still plenty to get an overview, or not?

  3. chriskresser says

    Glad it was helpful, Robb. A1c was my nemesis for quite a while. Couldn’t explain strange blood sugar patterns I was seeing.

    Alex: CRP is a good measure of systemic inflammation, and has some correlation with CHD, but lowering CRP doesn’t necessarily lower CHD risk. So there’s some murky water there.

  4. barbara shapses says

    Last week my doctor told me I had an A1C level of 6.8 and my doctor told me to lose 20 lbs. My glucose level was 105. Do you agree with my doctor

    • Amit says

      Yes Barbara! You have to start taking care of yourself! You should visit doctor and see if he suggests you some medication! I had sugar of 126 but HbA1c of 5.7, but still my doctor suggested me medications, exercise and controlled diet… by Exercise I mean brisk walk is also fine but on regular basis. Also I followed 5 things he had to tell me to pay attention to… No Potato, No Sugar, No Fine Wheat Flour.. thats Cake and white bread and stuff.. brown bread is alright in small amounts.. say 4 slices in breakfast is alright.. Drink Lot of Water… and Exercise regularly… and I was able to reduce 20 Kilos in 6 months…. and I am in a healthy range now… things are fine.. and I am off medication… I had to take 6 tablets a day… Hope this helps.

  5. susan says

    i have similar numbers to barbara above, and also wonder how worried to be. i am about 35 lbs overweight so i know that’s part of it but i remember being surprised when i attended a pre-diabetes class at kaiser that at least half of the folks there were normal weight or even quite thin. my fasting BG has ranged in the upper 90′s to low 100′s for several years now.

    • Amit says

      Yes Susan! You have to start taking care of yourself! You should visit doctor and see if he suggests you some medication! I had sugar of 126 but HbA1c of 5.7, but still my doctor suggested me medications, exercise and controlled diet… by Exercise I mean brisk walk is also fine but on regular basis. Also I followed 5 things he had to tell me to pay attention to… No Potato, No Sugar, No Fine Wheat Flour.. thats Cake and white bread and stuff.. brown bread is alright in small amounts.. say 4 slices in breakfast is alright.. Drink Lot of Water… and Exercise regularly… and I was able to reduce 20 Kilos in 6 months…. and I am in a healthy range now… things are fine.. and I am off medication… I had to take 6 tablets a day before… Hope this helps.

  6. says

    I’ve been warning about this for some time, but not had time to post on it. This is another example of using a statistic that is useful for populations for individual evaluation – and it can be very inaccurate for the individual. One reason that I stress avoiding lots of measurements.

    I think it’s possible that with reduced oxidative stress red cells could live even longer than normal, as I see perfectly healthy people on PaNU/ Paleo 2.0 diets all the time that have this pattern – low pp BG, no history of DM, good body comp, etc. They have an A1c of around 5.8 or so, then they read Jenny Ruhl or Bernstein and think they are going to die. In my experience, the diabetics or those with history of metsyn seem to achieve lower A1cs than the formerly healthy. There is just no logical reason to think a type I diabetic on Bernstein’s diet is with A1c of 4.8 is actually healthier than a non- diabetic would be on it with A1c of 5.6. I favor red cell survival as accounting for the difference, but it may have to do with de-glycosylation enzyme activity as well – we have such enzymes trying to undo the damage and their activity may depend on how much oxidative damage is going on – pure speculation on that.

    As far as recommendations, I recommend getting A1c and if it is below 5.5 you are done. If it is 5.5 to say, low 6s, do 24 hr and pp bg with fingersticks. If it is much above 6, then confirm it is high with fructosamine.

    PS – for reference, my A1C is 5.6, Stephan Guyenet’s is 5.8. Peter’s is 4.8. Peter is the only one who was ever overweight or had signs of metabolic syndrome among the three of us. Purely anecdotal but interesting. I did a 24 hr BG when I ate VLC and when my A1c was 5.6. The actual BG values correlated with an A1c that should have been about 5.0.

    @Robb

    I was planning to discuss this on your podcast, but it hasn’t happened yet ;)

  7. says

    @Barbara and Susan.

    All health measurements are contextual. If you are eating a diet that has some carbs in it, and your A1c and fasting BG are both high – they are concordant and telling you the same thing – you have poor glucoregulatory control. No need to confirm with fructosamine when fasting BG is high also – over 100 is high.

    Eat VLC with enough low GI carbs to stay out of ketosis – split between lunch and dinner.

    Magnesium 400 mg/ day as citrate (cheaper) or malate.

    Resistance exercise 1-2 x per week.

    Try that, and if numbers don’t come down in a few months, talk to your doctor about metformin

  8. Curt says

    THANK YOU! I’ve been trying to figure out why my A1C was higher than it should be (close to 6) after a three months of very strict paleo. Now – 9 months into paleo – I rely on a glucometer. Those numbers are great. Fasted is usually in the mid 80s. Virtually every meal I consume keeps me under 110. I’m pretty confident saying that my BG has not been above 120 in the past 6 months and is actually rarely even over 100.

    One weird thing though: My waking BG is one of my higher readings of the day – mid to upper 90s. I actually rises during the night. Sleep is solid, chow is great, exercise is good. Not complaining too much. 9 months in and I’m down 60-70 lbs, BP is down about 30 pts sys and dys, and bloodwork is great. I have plateaued pretty hard the last 2 months. Gotta figure that one out.

    Thanks again! This explanation of A1C is super helpful!

  9. Kelly A says

    Thanks so much! That explains why my A1c is always around 5.6 when checked every 6 months but my glucose readings were great on the nasty 3 hour glucose tolerance test, despite eating lowish carb until a few days before the test and definitely not accustomed to such a large bolus of sugar.

  10. Beverly says

    Thank you for the clear explanation. My fasting blood sugar has always been quite low. I participated in a “Community Health Fair Screening” and they sent me a letter telling me I had an A1C of 5.7 and was pre-diabetic. I was a little freaked out! Then they sent a letter saying there had been irregularities that day, and everyone needed to be re-tested. I was reluctant to go to them again, given that I was just a little annoyed. I went to my doctor who again checked my fasting blood sugar. It is low, as usual. She said she would not recommend A1C unless fasting blood sugar was elevated. She also said that getting that test done would indicate that I was suspected diabetic, and that would not be good to have on my medical records. I was still a bit concerned, but your explanation has made me less concerned. I can see how both the numbers could be accurate, and not in conflict. Thank you.

  11. says

    I love how your posts bring enough science to the forefront so that practitioners (like myself) can make us of it but so that the everyday person can read it and make some sense of it as well. This is a very thorough overview of a marker a lot of us are watching with our clients, so thanks!

  12. Anup Kumar Mukherjee says

    Thanks for this information. My A1c generally varies between 6.3 to 7.3 and my fasting sugar remains around 75 to 90 but my PPsugar, two hrs after meal is always between 250 to 270. It never goes down to 200 level. I am on insulin and any higher dose leads to hypoglycemia. Interestingly the ppsugar drops very fast after 3hrs. Is it a delayed action? So how ppsugar can be taken as an yardstick?

  13. Matt says

    Just got my first lab test back (life insurance required it). Since starting low-carb, high-protein 9 months ago, and regular CrossFitting, I figured I’d have stellar results.

    Glucose: 80
    Fructosamine: 1.73 (HIGH)
    Hemoglobin A1C: 4.8

    Because I was told not to eat/drink for 6hrs, I don’t have a post-meal glucose level. Anyway, the fructosamine level is freaking me out. I’m 5’9″, 155lbs, with very little body fat. Should I be concerned? I bet my life insurance company is doing to ding me.

  14. Maria says

    Hi Chris,

    I’ve heard conflicting results about the effects of iron-deficiency anemia on A1c levels. I had an elevated A1c of 5.8, and my GP said that anemia falsely lowers A1c, while an endocrinologist said it can falsely raise it. My ferritin level at the time were very low (4, since increased to 14). I’m a runner with a low BMI and low blood pressure and no other indications of metabolic disorder. Can iron-deficiency cause a falsely high A1c?

    I’ve also struggled with amenorrhea for over a year (PCOS has been ruled out). Can anemia can affect menstruation? Again, I’ve gotten conflicting responses from my doctors.

    Thanks!

  15. Deborah Henderson says

    Hello I am awake and can’t sleep because my Dr. thinks I may be prediabetic! My finger pricks taken over two weeks show after a full meal at the end of the day 80 or 85 . But when I had a fasting (2x’s) Blood work my Blood Glucose is 6.3 . I am home and had to retire due to a back injury fom work and this has limited my activity levels so much. I am slightly overweight , my chol is a little high 230 my trigl are good and my good chol is good . Can I really be pre diabetic or can it be from the pain meds and other meds I take fo asthma ,that I got when I was 40 from severe re-flux(had surgery fo reflux in 2005) Last I took advir disk 250/50 just before fasting Blood work . No family member ever had diabeties, high blood pressure ,high chol ,yes! I’m scared. Thanks so much

  16. Afshin Siadat says

    Hi Chris, Interesting article you have. I have a lot of interest in this subject because I was concerned with my blood test that I had this past October. I am a 22 year old male in good standing health. I was shocked to see that my hemoglobin a1c level was 5.3%. The fasting glucose was 83 and I started to test my blood glucose at home with a home tester, and the highest 1 hour glucose reading I had ever had post-pranial was 134, and most often my one hour reading is between 90-120 depending on which type of carbohydrates I had eaten. Those seem to me based on my research as a person with a normal range. The main reason for my post is I was hypothesizing that maybe the fact is that I have high blood hemoglobin levels, and I am a competitive athlete, that is it possible that I have red blood cells that live much longer than 120 days? Do athletes that do a lot of altitude training in order to increase their oxygen uptake increase the lifespan of their red blood cells, thus verifying why my hemoglobin a1c was over 5%? My next blood test I am going to do a fructosamine to have a comparison. From the best of my knowledge, the highest fasting blood glucose I have ever recorded was 85 when looking at all my blood tests from age 15.
    Thanks,
    Afshin

    • Chris Kresser says

      An A1c of 5.3 is perfectly normal. That’s nothing to be concerned about. Your other blood sugars are normal as well.

      • phileda erskine says

        April 2012 A1c was 4.1
        August 2012 A1c was less than 4.1

        I’ve lowered my Lantus dose and will get lab test in 90 days.

        Is Is there anything else I should be doing?

        What are problems/risks with this A1c level?

  17. Debbie Gries says

    hi – I am like others and have been freaking out b/c my practitioner told me I was pre-diabetic with a HgA1c of 6.0 but my triglycerides are only 55 and HDL is 68, over all chol 198. I am 5’4″ and 125 lbs. Yes, I eat sugar and wheat but also eat veggies, good fats, etc. The 6.0 just seems so out of whack compared to my other numbers which have actually improved over the last year. Should I investigate more or just have another test in 3 mos. (I am making sure to exercise at least 30 min 5 days/week)? Thank you!

  18. says

    Great article Chris! Thyroid can also skew the results due to its effects on erythropoiesis. I have a few hypothyroid patients with normal fasting and post prandials whose a1c’s were elevated. After getting them from hypo to euthyroid, A1c came down! Just another interesting tid bit!

  19. lue ann says

    I have anemia and not much appetite. I recently had an A1C test and my Dr. said my A1C was 6.3. I am freaking out because he also said I am pre diabetic. I test my blood glucose 3x a day and it is always in the high 80′s in the morning, 90′s at lunch and night.

    • Chris Kresser says

      You need to test your blood sugar just before a meal, and then at 1- and 2-hours after. If you’re below 140 mg/dl at one hour and 120 mg/dl at two hours, and your fasting glucose is normally in the 80s, I don’t think you need to worry much about your A1c. As I said in the article, it can be affected by red blood cell turnover, which would be altered in anemia.

      • maureen says

        Hi dr. Kresser
        I have a number of autoimmune diseases. 12 in fact. Today I saw a new specialist for my diabetes. I have had 3 blood transfusion in the last six month. I have ever scope you can think of each time. I even swallowed the capsule camera and there is no sign of bleeding anywhere. I have celiac and biopsies were taken during the scopes and the results turned out to be normal. My blood sugars are uncontrollable at times If stressed they rise to the high 20s and if I take insulin before I get home I am having a low at 1.9. I will get up, blood sugars at 6, eat breakfast and take 5 units of humalog and get to the doctors and my blood sugar all have risen to the high 20s. Today the doctor mentioned in passing that it could be my body is rejecting the insulin. Can you explain this.
        Maureen

        • says

          Hi dr. Kresser
          I have a number of autoimmune diseases. 12 in fact. Today I saw a new specialist for my diabetes. I have had 3 blood transfusion in the last six month. I have ever scope you can think of each time. I even swallowed the capsule camera and there is no sign of bleeding anywhere. I have celiac and biopsies were taken during the scopes and the results turned out to be normal. My blood sugars are uncontrollable at times If stressed they rise to the high 20s and if I take insulin before I get home I am having a low at 1.9. I will get up, blood sugars at 6, eat breakfast and take 5 units of humalog and get to the doctors and my blood sugar all have risen to the high 20s. Today the doctor mentioned in passing that it could be my body is rejecting the insulin. Can you explain this.
          Maureen

  20. James A says

    I just got back an A1C of 5.8, which shocked me. I spent a few weeks testing my fasting blood sugar, and it ranged from 75- low 90′s. I also have tested my postprandial levels at 1 hr and 2hrs after purposely high carb meals (for testing purposes only). Prior to eating, I had an 84 mg/dl, then I ingested a bagel, 2 cookies, and a tall glass of orange juice. One hour after, I was at 123 mg/dl, and 2 hours after, I was at 98 mg/dl, and 3 hours after, I was back in the 80′s.
    My question is, my prior A1C was done during a routine physical in 2009 , and resulted in 5.2 . The blood work was done by Lab Corp, which stated a reference range of 4.0-6.0. This time, my doctor’s office ran the blood work themselves, and I resulted in a 5.8, and their reference range is ” 5.5% – 7.0%”. Could this mean that if my blood work were tested at Lab Corp again instead, I may have had a lower A1C?

    • Chris Kresser says

      A re-test wouldn’t hurt, but as I said in this article it’s not an especially reliable marker in individuals. If your fasting and post-meal blood sugars are consistently low throughout the day, I wouldn’t worry about a slightly elevated A1c.

  21. Martin Bratcher says

    Hi Chris,

    Thanks for the great article. I am 34 yrs old and recently was diagnosed with type-II. My first A1C was 7.3 and the latest A1C i.e. my second was 5.5. However, I used to check my sugar level using glucometer during last three months – each day one reading – 1 hr before and 1 hr after (fasting, lunch, supper and dinner) and it consistently averaged 170-180. But suprisingly, my A1C was only 5.5. I also tried my glucometer with one other glucometer couple of times and it seems to be same. Do you think this is normal and I should rely A1C result (irrespective of the fact of RBC’s life). Do you think fructosamine test would be more reliable for me?

  22. Rose says

    I had my AC1 test without fasting and the reading was 6.8 my doctor already wants me on metformin, can I try diet and exercise first or should I not wait and get on this medication. My glucose in my urine is at normal levels (84) Please advise

  23. Steve says

    “Another condition that affects hemoglobin A1c levels is anemia. People who are anemic have short-lived red blood cells, so like diabetics, they will test with falsely low A1c levels.”

    FYI Iron deficiency anemia actually causes an elevated A1c. This is a common misconception. Providers sometimes believe pts with microcytosis or a low MCV anemia, that the binding of sugar to the heme group is lesser than normal MCV levels or that the smaller the RBC some how reduced the A1c % concentration. Research shows the opposite is true.

    • says

      I am a 73 year old male with early stage MDS. My RBC is 11.4, fasting BG is 133, and A1C is 7.9. My doctor says I need to start medication to manage my BG. What do you think? Do you think I can manage my BG levels with diet and exercise? I currently am on a diabetic diet and ride a bicycle about 30 minutes per day. I also walk about 30 minutes a day. My weight is 200 and I am 6 feet tall. My cholesterol and triglycerides are normal.

  24. ICDogg says

    Thanks for the info explaining long-lived RBC. This would explain the extended lag time for lowering my a1c, which continues to get lower each time I test it but not quite as quickly as I expected based on the assumption of an “average of the last 2-3 months”.

    6 months ago I was over 13, I’m just above 6 now, trying to get under 6.

    I do test regularly an hour after meals, and it is never over 130, as a result primarily of low carb eating.

  25. ICDogg says

    BTW I’m not a big Wal-Mart guy either but they do have home a1c tests that are about $9. You send your sample to a lab and get the results on-line. I did one the same time I had one from Quest Laboratories and it came within 0.1.

  26. Patricia says

    I had gestational diabetes with my last two kids. I have been eating healthy and walking five days a week for one hour. In January I had a A1C done,I had a 107 glucose and my A1C was 5.6. I had it done again two weeks ago now my glucose is 79 and my A1c is 5.7. I lost 45 lbs. Why did my a1c go up? My doctor said I am fine. He also did other lab work and everything came out fine. I dont want to become a diabetic thats why I am taking care of myself.I dont have high cholesterol. How often should I check myself?

    • Chris Kresser says

      A1c isn’t a particularly reliable marker for individuals as I’ve pointed out in this article. I’d go by your fasting glucose and, more importantly, your post-meal glucose. If you’re staying below 140 mg/dL one-hour after meals and 120 mg/dL 2-hours after meals, that’s a good sign.

  27. Hughena N says

    My first a1c test was 5.9. My doctor ordered a glucose tolerence test .My fbg was 94 and my 2hr post after 75 grams of glucose was 105. My a1c at that time was 6.2. I weight 128 lbs . I have lost about 7 lbs from when the first a1c was done until my the second one. Do I have something to be concerned about? There is diabeties in my family.

  28. Simon says

    Just got back from the docs after 2nd blood test in 6 months, started high fat, low carb (under 50 grams) and med protein in feb this year, first blood test was normal back then according to doc. Today he said you are pre diabetic and have hyperlipidemia. TC was 291 and TG 205!! HBAc1 was 5.7 (NG SP), the blood test was taken first thing 8AM after a short fast of 12 to 14 hours since night before. For 2 months have had no starches, only veggie greens and protein and fats. Now my family wants me to stop eating this way ASAP! Don’t know what to do? 46 yrs, 82kg and 12% body fat. Lost 10kg and halved the body fat in 6 months, so why am I now pre diabetic according to my doc? And must eat normally or I might kill myself….

  29. David says

    Hello Doc,

    I had a recent blood work come back with my Glucose serum at 92 and my A1c Hemoglobin at 6.1. I have made changes in my diet and excerise now. Am I at risk for diabities at 10 to 15 years from now or should I be fine? I also lost 8 pounds in the last three weeks from eating better.

    Thanks
    David

  30. othelzer says

    hey have you ever read Dr. walech “dead doctors dont lie” and his reomendation of cromium and vanadium for diabetes. is this a real deal you have heard about or is it a scam?

  31. Katie says

    My sister is 35 and a survivor of leukemia when she was a child. She has been diabetic for over 10yrs as a result of the chemo and radiation used for her treatment. Her daily readings are about 90-120. However, her A1C continues to skyrocket. A little over a year ago it was around 7.5 and is now up to 8.5. She’s barely 5ft and weighs only 90lbs. She’s not your standard patient since she suffers from several other late effects of the radiation, including osteoporosis. And she is very regimented regarding her diet. Any suggestions on why the A1C is so high?

  32. Angela says

    So i went to er tuesday with chest pain and palpitations. Found out i was having psvt. Thry found out from blood work that my blood sugar was 209 at the time. So i went to my dr the next morning for blood work. My a1c was 5.8 and bs was 100. He didnt seem to concerned about that. But i have been checking my bs at home, got 130 fasting and today i got 239 2 hrs after i ate a bowl of oatmeal with sweetner and a cup of decaf coffee with sweetner and cream.

  33. Re says

    That’s a great relief. I lost my peace of mind with this A1C diab thing. I got 5.7 and I was told the same, insulin resistance issue could be there. Oh God, I’m trying for baby I do not want to get onto more pills n troubles.

  34. Ashley says

    My A1C was low the last time it was taken. My doctor suggested I eat more sugar, but I already have quite a bit in my diet already. I’m a little overweight, too. Could this number be an error, and should I look into other options of raising my A1C or checking it another way?

  35. Dee says

    Hi there. New to type two. Well- I was on file I was 10yrs ago but lost 33kg and it wasn’t issue so they re considered it (but u don’t get rid of it- you just manage it well). Well GD turned into type two. But 2yrs of regular hypos (daily)- I got first a1C and its 4.9%. I was anaemic after son was born born but not been tested. Iv been testing FBG, pre and post meals. Fastings 5-5.8 so not bad. Pre and post meals are my issue more so post… 8-10mmol. Hypos are happening less
    Now and I can only assume the test in June will be raised? Or is that assumption not valid? Just started metformin. 2 days ago and numbers are up! And then I feel low but I check and its up!

  36. dnarex says

    How is anemia defined? I have normal hemoglobin and hematocrit but my serum iron and ferritin are very low (about half of the bottom value of the normal range). In the past, hemoglobin and/or hematocrit have been slightly low.
    According to Mayo Clinic, low hemoglobin will give false low results on hA1c whereas low serum iron will give falsely high results. Based on that I would assume my 5.2 is higher than the result would normally be because of the low iron. If I am classified as anemic based on ferritin and serum iron, then presumably my red blood cells are short-lived and my hA1c should actually be higher. Based on hemoglobin and hamatocrit, I wouldn’t be anemic and the test would be fairly accurate.
    I am not sure how to interpret the results.

  37. Stev says

    I am glad to finally find some possible answer to my puzzle. For I may have the exact opposite and potentially harmful circumstances. My fasting and post meal glucose puts me in the diabetic range and has for the last 5 or more years (age 55). Almost always it’s at least 120+ fasting overnight. However my A1C has consistently fallen in the under 5 range every six months since then as well. And neither the doctor nor anyone else I asked could explain that. So I’ve grown comfortable thinking I wasn’t really a true diabetic.

    Seeing a logical explanation now is going to get me motivated and back on track with diet and monitoring.

  38. Cari says

    I want to thank you for sharing your research, experience and knowledge. I have been diagnosed with gestational diabetes and based on how my endocrinologist approached my care, I feel pretty strongly, she was more interested in writing a prescription than providing the appropriate guidance and strategy to managing my GD.

    Also gauging from how my Mom was treated for her pre-diabetes, it seems to me that *some* of today’s doctors are motivated by external sources to diagnose and treat diabetes with specific drugs (pills or insulin). I am appalled that by the one hour test, this dr preferred to put me on a mid-range dose of Gliburide which is not FDA approved for pregnancy and only has a 10 year history of use during pregnancy. Thankfully, I am educated and confident enough to take some control in my own care and opted to attempt to control my blood sugar with better diet and exercise. In 12 weeks, I have only had 3 “high” readings and those 3 were after splurging on a refined sugar product and after 2 hours, my level was 107 or under.

    I think it’s dangerous and irresponsible for doctors to diagnose based on single test results which, as you state, do not mirror real life and so logically, cannot possibly tell the whole story. I believe if more doctors subscribed to your theory of the variety of tests to show the entire picture, we might get a better handle on diabetes, gestational or not.

    The bottom line is that the way this doctor treated me has damaged the trust I have for the care I am receiving. I encourage everyone to ask questions and do what feels right for themselves as, unfortunately, some doctors don’t have the aptitude or make the time to care enough about the individual to make the right choices for care.

  39. Melissa says

    My blood sugar levels are great when I’m not pregnant, but at the end of my pregnancies (2 so far), I have glucose in my urine. My postprandial numbers are normal, but my A1c was a 6. My healthcare provider was very concerned. Here I am now pregnant with an unexpected bonus… I confess, the thought of going through so much testing again is so stressful. I feel great, and we are far from a sedentary life style (my boys and I walk 4 miles every morning). And we eat a balanced wholistic diet.

    So really what I’m saying is thank you for helping me feel normal, even though my healthcare providers insist I’m high risk. What a joke.

  40. Nick says

    Hi,
    I’ve got some problems with the study you posted. So, the researchers took data from 23 subjects, who were diabetic and compared this to the normal range in the population. 23 is kind of a low number, but worse is that there was no control group. I know this is a little nit picky, but I have never been to their lab, I don’t know if the equipment they are using to determine hemoglobin lifespan is accurate. I feel that more research needs to be done before we can discount HbA1c. Specifically a larger study with a control group.
    I’m glad you are getting a conversation going about the topic, and I was not aware that this was a possibility.
    Thanks!

  41. Tricia says

    HI Chris,

    Just read your article and wonder if i may be a person whose hemoglobin is around a lot longer. 3 years ago i was told i was in the prediabetic range.i forget the number sorry! Anyway, i had a baby 2 years ago and did not have gestational diabetes. Is that uncommon to have a high ac1 and no gestational diabetes? (although i did have a 10lb baby). today i weigh 123lbs and am 5feet 2inches and in the past 6 months my ac1 has been tested twice and came back at 6.3 both times. Should i have my dr. give me the post meal glucose test?

    thanks!

  42. JohnM. says

    Thanks for the article clarifying the diagnostic parameters in assessing when a person is ‘pre-diabetic’ or ‘has type Two Diabetes’, after a naughty, naughty ratio with the hemoglobin A1C. I feel fine, and am a bit overweight. My doctor telling me with a ratio of 6.9 with the hemoglobin A1C, now I have type two diabetes. Well, maybe not, since like I say, I feel fine. I am a persistent walker, mover, and shaker, pardon the cliches, and used to be a long distance runner. guess my red blood cells like my Swiss ancestors, may live quite awhile. giggle, huh, a bit. I think I will lose the twenty pounds afterall, and give the ratio what not, another spin, with less gin. uhhh, sugary lifestyle. lol. John. Thanks again.

  43. E Hamm says

    I have daily after meal readings of 200- 365 and fastings of 180-199 but my A1c is only 8.1 I am on oral meds but the more they increase the higher my daily sugars. I also have antiphospholipid syndrome.

  44. Cheryl says

    Dec. 2011 I had a complete physical. My A1C was 6.2. I lost 20 lbs. and cut out sweets and limited my carbs. I was retested three months later and my A1C was 6.1. I read that broccolli reduces glucose. Well, I have been eating broccolli for almost two years with dinner … close to everyday. I went to my doctor Oct. 2013 for retesting. My A1C results were 5.6 and I eat rice, pasta, and bread whenever I desire ( in moderation). I also started taking Bilberry capsules once a day for about
    three months now. It is my opinion “BROCCOLLI WORKS! “

  45. Bob Jennings says

    My last A1C test was 9.5. When I check my blood sugars morning and evening they rarely go over 200 mostly around 150 and I am on 40 units am, 50 units pm before meals. Two shots per day. Many times I hit 120 to 125 or down to 65 if I get too low. Another diabetic says I will go on dialysis and loose my legs but I don’t believe that. I am 72 and still doing well. I have my doubts about this test. My body always has been in the 8+ A1C range. My doctor said to increase my morning shots. Well I did and had a very low blood sugar early afternoon. I just don’t see how why I strike that high on the AIC tests? My friend is severe diabetic and goes anywhere from 50 to 350 all the time yet he comes out with a 7 on his A1C. I seem to be much healthier than he is. This is why I looked up this article. I don’t think the A1C test is at all accurate.

  46. Mary Katherine says

    From what I’ve read the studies on anemia are conflicting. It’s been found that anemia raises a1c, lowers a1c, and has no effect on it. Here is information from a study in India (reported 2 years ago) that said anemia falsely lowered a1c. However they said prior results were conflicting so they did their own study, and the conclusions were not supported elsewhere. They said further study is needed.

    I don’t know anything about other research, but they differentiated between mild, moderate, and severe anemia. It appears that all of the patients had either moderate or severe anemia. I have mild anemia and it appears none of the patients had this. At any rate the doctor told me not to worry about it. I think just saying anemia may not be sufficient; also this study only considered iron-deficiency anemia.

    But I’m a diabetic with an a1c in the normal range without meds (5.4%) but it’s a good reminder not to get complacent and test blood sugar. b/c if I slack off things can go the wrong way. My hemoglobin is 11.3.

  47. Ken Orland says

    Chris,
    Just had a checkup and my fasting glucose was 110, last year it was 120. Both years my a1c was well within normal levels. My dr wants me to diet and exercise and recheck blood in 3 months. I am a very anxious person and the dr feels this can raise the fasting glucose. What would you suggest?

  48. Elaine Puricelli says

    What about people like myself?
    My A1C number didn’t change much at
    all after my distal pancreatectomy.
    But aren’t I now at a bigger risk of
    developing diabetes post-operatively,
    in the here and now since I can’t replace
    the pancreatic tail?

  49. Norm says

    I have been on metformin ( 4- 500mg/day) for 1 year. My fasting BG is between 95-106. 1 hour after meal its 125-130. My A1c was 6.9 3 months ago and recently it rose to 7.4.
    My triglycerides are 120; LDL 90, HDL 45.
    Not sure what changed. I have lost 10 lbs since last year as well. Any suggestions as to what I can do to lower my BG and A1c?

  50. Vivian says

    Hi There.

    I am 44 years old and female. 45 in May, 2014.

    I am 5 feet five and currently 202 lbs.

    I was 213 lbs in December 2013 but am losing weight following a semi Paleo diet. I am not eating grains, beans or added sugars.

    I take that back. I have had some agave, and organic peanut butter/chocolate with very low added natural sugar. I do eat fruit.

    I still have some dairy. Not a lot. No ice cream or cheese.

    I have coffee everyday with organic cream. I have had plain, whole fat organic yogurt.

    I have been doing this for nearly a month now.

    Before I started my AIC was 6.3 and my fasting blood sugar was 102. (January 2014)

    My primary care physician and endocrinologist said I was pre diabetic but not diabetic.

    I didn’t have any blood sugar issues until I was 42.

    (As far as I know.) Last time I was checked I think I was 34 or 35.

    In my late 30′s (36-38) I exercised a lot and ran races and 2 full marathons. I didn’t really watch what I ate per se but my weight was around 170. Still overweight but physically spry.

    Then between 38-42 all that went by the wayside.

    My weight went over 200 lbs and I just ate whatever.

    Then I lost 40 lbs at 42 yrs of age but then gained it all back.

    It was at 42 I found out my blood sugar was 102 fasting. It had (as far as I know) never been over 100 before.

    While I was working out and watching what I ate in my early 40′s my fasting blood glucose came down to 94-96. My AIC was 5.8 – 5.9.

    I have always struggled with weight since I was a teen. I was diagnosed with PCOS at the age of 29.

    I am a sugar addict big time. Intellectually, I KNOW what to eat.

    I know when I am eating junk I know how dreadful it is health wise.

    I do have high cholesterol and Triglycerides.

    It was 311. LDL over 200.

    After 3 weeks of semi Paleo my AIC came down to 5.7. But my fasting glucose was 104.

    My cholesterol came down to 295. LDL is still 205.

    (My blood was drawn February 10, 2014)

    Here’s the thing. How do I get a Fructosamine test done?

    My Endocrinologist said it was the same thing as AIC.

    I want to get a blood glucose test done as well.

    I have no clue what my post meal blood sugars are.

    How accurate would they be now since I am following a much healthier food plan?

    What would they have been when I was eating cake and ice cream?

    Maybe I was diabetic post meal and fructosamine wise but not AIC and fasting blood sugar wise three to 4 wks ago?

    I am confused and scared.

    Will a potato and rice post meal test be as accurate as a sugar drink test at the docs office?

    I don’t know if my Endo will perform a blood glucose post meal test?

    What do you do? Hang out at the docs office all day?

    Ok thank you!

    I know this is long!

    Best,

    Vivian

  51. Teri says

    I was diagnosed in 1986 with gestational diabetes with my second pregnancy, and took insulin twice daily. As expected, after I had my daughter, my sugar levels were normal. But I was told to expect to go diabetic when I hit about 40. I had normal BG levels into my early 40′s. At 42, I was diagnosed with Hep C (much to my surprise), and did a 6-month ribavirin and interferon therapy. It wreaked havoc on my body, including my red blood cell count. Shortly after treatment commenced, my doctor called to tell me that he wanted to put me on metformin. I was taken off of it about 6 months later because he said that my a1c was normal. I was about 108 lbs at the time. I gained about 16 lbs about a year later, so I expected to be diabetic again. I asked to be tested, and again was told my a1c was normal. I tested myself with my glucometer, and had high fasting sugars, and high PB’s. I went back to my doctor and told him about my readings. He brushed it off, siting that the a1c is normal.

    It has now been 7 years since I was taken off metformin, and I KNOW I am diabetic It is in my family history; mother, grandmother, sister. I don’t know how to convince my doctor otherwise.

  52. Tiffany says

    Hi Chris,
    This is such an informative article. I would like to know the best time to check my post-meal glucose.

    Thank you.

  53. Cam says

    Thanks for helpful article, Chris.

    I’d like to add, however, that A1c results can be skewed both upwards and down by in response to differing kinds of anemia. With iron-deficiency anemia, for example, my understanding is that A1c results can be skewed misleadingly high.

    The A1c test is complex and controversial, as you have pointed out.

  54. Bob Jennings says

    I am glad I found this article. I used to worry about my A1C all the time and believe the worry raised my blood sugars. After the latest article where the person say’s they can relax now and not be stressed was nice to read. I am 72 now and have regularly run high A1C’s mostly in the 8′s and also in the 9′s since I have been checked by this test yet I have no trouble with any diabetic problems. My eyes are fine and all my organs. So I never have been convinced the test is the God’s truth! I have been on insulin since 1995. I told my Doctor about this article but he dismissed it and said “You can’t believe everything you read on the computer”. Well as a living example of the way I respond to A1C tests I think I am! I am sure my blood cells are the rebellious type to this test by now. I am not worried at all about it anylonger!

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