Does this A1C pattern seem realistic?

Been diagnosed T2D since 2005. Insulin of some sort (ending up with V-Go) for at least 10 years. Peaked A1C of 9.5 in May 2020, started CGM in Oct 2020, and t:slim pump in Nov 2020. Below 7 A1Cs after taht.

Quit my job (early retirement) and started exercising regularly (10k-20K steps per day) in July 2020.

A1C of 4.9 last week??? My daily insulin unit use is over 100 units, and I know I had only 1 day of experiencing low BG (~60) in the past several months.

This has to be wrong, doesn’t it?

Are you on a Descom CGM? If you are, then you can historically track and compare your GMI index to your A1C. Although the values will most likely not be identical, the GMI trend line should mimic your A1C trend line. Your A1C could also be an outlier, especially if done in a doctor’s office using a desktop A1C analyzer as those are not calibrated and certified and can be off by up to 1%. You can also always go to a local lab that uses Quest Diagnostics to process their bloodwork and you will get a certified result within 24 hours or so. A test is currently $21 and they often have coupons up to 50% off. You can see a typical website where you can order a test in your area by going to

Thanks - this was a Quest report. According to my CGM, the 90 day average covering the same amount of time is 121 (and i am thrilled, definitely), but that roughly equates to a 5.8 A1C, versus 4.9. I dunno, perhaps that is within the range of error, but 4.9 was a shocker.

Nope between Quest and Dexcom, that is about .5% out of tolerance. Expect to get back closer to normal on your next test, but either way looks like you are now in great control, enjoy and don’t stress the small stuff.

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From a type 2, these 2 things are related, at least for me. I had great improvement when I retired. I think that was the reduction of chronic stress. I was free to do more exercise. Both stress relief and regular exercise are as important as proper diet, medication and insulin.


Off hand, I’d say could be biological variability. Also, the older HbA1C formula was based DCCT data. If I’m remembering; correctly, the data was from point in time lab tests. GMI is based on a more recent data set that might be CGM data.

IMO, both are out dated since neither accounts for highs and lows. Time In Range is a much better measure of BG control.

My A1c is 4.6, but I take both B12 and folic acid. Both lower A1c. Are you on any supplements which could lower yours?

Time in range is really outdated as well because as diabetics, we are all different, yet the standard range is set to 70/180 mg/dl for all of us. It is a good starting point but many of us that insist on tight control set our range delta much tighter in our Dexcom application. For those that low carb, the range low also often starts much lower than standard.

Dexcom also allows for 2 ranges so I set both a day range and then a tighter lower night range.

The Internaitonal Consensus on TIR allows for customization. So TIR, at least as it pertains to the international consensus, is not outdated.

Just be careful with the lows. It’s been proven that low blood sugars cause serious heart damage. It’s better to have a sugar of 200 than a sugar of 50. Speaking from the heart.

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I don’t agree. Low blood sugar “can” cause a serious heart event such as myocardial ischemia and cardiac arrhythmia, more prone in some individuals than others based on several factors. There is no guarantee that heart damage will occur running low blood sugar. High blood sugar on a regular basis will eventually cause considerable, non reversible damage to the body.

Without going into lengthy details, please share what you can related to low blood sugar causes serious heart damage. I am always eager to learn something new. Not looking for an argument, just eager for facts. Thank you.


I am quoting doctors words here. I am not making this up. Everybody thinks high sugars high sugars fine. But what is the range of high sugars? Not 200 or 180. Maybe over 300 sure over years yeah you’ll lose a leg I’m sure. But no, thats not what I’m mentioning. I am quoting what doctors have specifically told me. And this is new research that has been proven. Low sugars can cause serious heart damage. Like heart attacks in your sleep type stuff. That’s all I can say.

According to the Joslin diabetes center:

Your physician will define for you what your target blood glucose should be — identifying a blood glucose target that is as close to normal as possible that you can safely achieve given your overall medical health. In general, high blood glucose, also called ‘hyperglycemia’, is considered “high” when it is 160 mg/dl or above your individual blood glucose target. Be sure to ask your healthcare provider what he or she thinks is a safe target for you for blood glucose before and after meals.

If your blood glucose runs high for long periods of time, this can pose significant problems for your long-term — increased risk of complications, such as eye disease, kidney disease, heart attacks and strokes and more. High blood glucose can pose health problems in the short-term as well. Your treatment plan may need adjustment if the blood glucose stays over 180 mg/dl for 3 days in a row. It is important to aim to keep your blood glucose under control and treat hyperglycemia when it occurs.

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I am working on a related project and believe that you are conflating cardiac events such as myocardial ischemia and cardiac arrhythmia with serious heart damage.

OK, I found this paper on severe hypoglycemia and heart issues. I did not read the paper carefully but scanned it. I could not see where there was a definition of what severe hypos are. For me, anything below 50mg/dl is awful feeling. I once had a hypo while riding my bike that was in the 40s. I wouldn’t need a heart attack for that to kill me. I was weaving pavement edge to edge with my brain saying, “There’s something wrong with this bike.” HA HA, The bike was fine, my brain was not.

As to hyperglycemia, once BG is >180mg/dl damage is being down to the finest blood vessels such as in the kidneys and retinas.

I found this chart that shows severe hypo a <40mg/dl

There is quite a bit of documentation on heart issues as I stated above as in cardiac events related to hypoglycemia. It was the serious heart damage that I was questioning and have never seen or heard of.

Ok now we’re getting into a conversation here. Yes 80 to 180 that i was told was the normal range like 35 years ago ok. I know that. Yes long term high blood sugars obviously. But what you’re not considering is the insulin you’re taking. How long it takes for the insulin to react in your body along with how long it takes for your body to digest the food. If my sugar goes to 210. I’m not worried about it, because I take insulin and it will lower to a normal range eventually. So there’s the doctor’s care that you’re talking about. But if i start adjusting and taking more insulin to lower my blood sugar because it’s slightly over the ‘normal range’, then in the end i dont really know how much insulin is in my body and that will lead to hypoglycemia, low blood sugars. Which, i repeat has been studied and proven to cause heart problems. I get what youre saying, but youre not listening or thinking about what i’m trying to say. Joslin is from the beginning. A lot of respect goes to him and the books he wrote, but this is new research.

Look I’m not a cardiologist. I consider a heart attack a severe heart issue. Sorry if I was conflating or what have you.

Thanks. I believe this agrees with what my doctor said. Again, i was just stating what i have recently been told by a professional doctor. Increased mortality. It says it right here. Even 1 low blood sugar. Yes it’s terrible. My sugars are in the optimal range around 72% of the time recently. My A1C is 6.8. Look none of us are perfect, we all do the best we can. Can we do better? Yes. And there’s many reasons why. I’m just trying to do the best I can. And this information is something i have to think about. I’ve had many lows in the past. Not as much now. Did i pass out on the floor? No. But if I’m sleeping, I probably would not wake up. So this information concerns me and scares me a little. I appreciate your post.

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Completely in agreement! And we are all here to try to learn to do better (and possibly help others to go so as well.)

The high sugar low sugar conundrum is an interesting one. But what’ll kill you fast? Low sugar. What will kill you slow? High sugar.

We aim for the best sugar we can and are grateful for the tools that we have to accomplish that goal.

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