# Is there a risk to slightly elevated glucose with normal A1c? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 21, 2025, 4:58am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292 "2025-04-21T04:58:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 4:58am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/1 "2025-04-21T04:58:02Z")
I decided to schedule regular blood tests so I can track my basic stats over time and see if there are any odd changes. I now have two about 10 months apart. One of the few outliers is a slightly high fasting blood glucose–103 mg/dL. It was 104 last year, so it’s stable. I had a long fast, 16 hours this time. A1c is fine, though, 5.2% in both cases. Anything to concern myself with? Not sure if it has any relevance, but I eat one meal a day and have negligible appetite or mood/fatigue/etc. effects from this. BMI of ~20. Do I just have especially stable glucose levels with low peaks and high dips? As an aside, I’m thinking of getting a CGM just to get a sense of where I’m at. Would like something that syncs with my phone. Is Dexcom considered reliable? Any other prescription-free options? ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 21, 2025, 6:24am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/2 "2025-04-21T06:24:32Z")
I’m not a doctor but why are you worried at those levels? Your fasting glucose is barely in the pre-diabetic range and your A1C isn’t even in the pre-diabetic range. My understanding is that the lifespan of your red blood cells can affect your A1C readings. If your red blood cells live shorter lifespans than the average person, your A1C will be falsely low. If your red blood cells live longer lifespans than average (average = 120 days) then your A1C will be falsely high. So hypothetically, if you have short lived red blood cells then your A1C will imply your blood sugars are not as bad as they truly are. However I have no idea how common red blood cells that live too long/too short lives and give false A1C readings are. However I have no idea if doctors are able to determine the average lifespan of ‘your’ red blood cells. Looking online, red blood cells can live from 70 to 140 days in different people. Other things you can try is your postprandial glucose. Blood glucose spikes after eating carbs. You can eat 75 grams of pure glucose and measure your blood sugar both before eating the glucose, 1 hour after eating it, and 2 hours after eating it. That can tell you how high your blood sugar levels spike. You can do this yourself at home by buying pure glucose online and getting a glucometer at a pharmacy. You can also have your insulin levels measured (not glucose levels, but insulin). If you have high insulin levels but normal blood glucose, that means you are insulin resistant and on the road to diabetes. ---
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [April 21, 2025, 6:37am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/3 "2025-04-21T06:37:15Z")
As a sometimes-prediabetic, sometimes-not person, my suggestion would be to err on the side of caution and always live by whichever blood-sugar reading is worse. You can’t go wrong with eating healthy, exercising, taking bitter-melon/cinnamon stuff to lower blood sugar, etc. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 6:41am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/4 "2025-04-21T06:41:50Z")
Not worried, just trying to understand the readings. “Pre-diabetes” sounds bad in isolation. But an A1c of 5.2% is normal. And according to online converter tools, is equivalent to 103 mg/dL. Which is pretty weird–shouldn’t my fasting levels be _lower_ than my long-term average? I’m willing to pony up a few bucks for a CGM rather than having to poke myself every time I want a reading. Not too concerned, more just curious what my daily readings look like. I’ve no reason to think I’m actually pre-diabetic; I’m not overweight, have no family history of it, etc. But I do find it a curious data point. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 6:56am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/5 "2025-04-21T06:56:10Z")
> [@Velocity](#): > > aking bitter-melon/cinnamon stuff to lower blood sugar Eh… > **[Momordica charantia for type 2 diabetes mellitus](https://pmc.ncbi.nlm.nih.gov/articles/PMC11836555/)** > > Momordica charantia (bitter gourd) is not only a nutritious vegetable but it is also used in traditional medical practices to treat type 2 diabetes mellitus. Experimental studies with animals and humans suggested that the vegetable has a possible ... > There was no statistically significant difference in the glycaemic control with momordica charantia preparations compared to placebo. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [April 21, 2025, 7:19am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/6 "2025-04-21T07:19:33Z")
CGMs are not pain free. They do stay on awhile. Guess what happens to your skin under there? I’ve worn them, continuously for 4 or 5 years. You have to switch spots around. Dexcom is a good brand. Stay away from the home grown hacks and cures. The only thing I was concerned with in your OP is you’re only eating once a day. I suppose if it works for you, it’ll be fine. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 7:39am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/7 "2025-04-21T07:39:18Z")
I’m certainly not planning on wearing them year-round. But it seems to me that doing a 15-day stint to get an idea of how my levels fluctuate isn’t a terrible idea. Interesting if nothing else. Thanks for the vote of confidence on Dexcom. One-meal-a-day works very well for me. And even after 24 hours, I’m not _that_ hungry. Just interested in eating at that point. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 21, 2025, 11:09am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/8 "2025-04-21T11:09:21Z")
I am diabetic. 12 years now. But very mildly diabetic and pretty careful with my diet & meds. Exercise not so much any more. Sigh. If I take a reading immediately post-wakeup but pre-coffee, they average about like yours: 100-105. But over the course of two weeks, the lowest will be 70ish and the highest will be 115ish. The point being the daily spread is large even though the average is quite consistent over months & years. And this for readings taken at a very consistent point in the physiological day. I would place little value on your two readings taken 10 months apart and both taken fasting, but also taken partway into your day’s activities. IOW, my take on your situation is to believe the A1C, not those two FBG readings. FWIW, late onset diabetes is a disease where you slowly burn up your pancreas by forcing it to overwork. Eventually as it wears out and dies off what’s left can’t handle the needs of your daily living and then the trouble really begins. The opportunity for early warning is not when your A1C starts rising, but rather when your post-prandial BG spikes are larger and last longer than they should. That’s the sign of a pancreas running flat out and not keeping up; taking 3 hours to do a 1 hour job. And those extra two hours of sprinting are what’s killing it. So your goal is to find out if you’re making it sprint, then if so, stop that through diet, exercise, weight loss, and, if necessary, meds. Like your heart, it can jog along 70 years no problem. Just don’t make it sprint several hours a day. I’m thinking that your one meal a day plan is probably contributing to overwork. Especially if that meal is carby or sweet. Which a standard American meal is quite likely to be, even if it seems pretty innocuous or healthy compared to a beer & pizza horror show. If I was going to pursue fingerprick testing or a CGM, I’d be real interested in looking at the dose/response curve after your typical meal. If pricking, one every 30 minutes post-meal until you fall back to baseline oughta do it. So 4 or 5 sticks. I know that idea sounds pretty off-putting at first, but after a bit of practice / experience finger sticks are no big deal. IME worst case they feel about like a static shock from a doorknob and best case they feel like nothing. The average is biased heavily towards the “nothing” side. Good luck. I agree w your attitude that this might be a sign of a problem or might not. But better to run some more experiments than to say “Ehh, who cares? More Pizza! More beer!!” ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [April 21, 2025, 11:38am UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/9 "2025-04-21T11:38:28Z")
I had the same concern as you. It turned out that my dawn phenomena was causing my higher-than-expected fasting glucose level. My doctor said since my A1C was okay I shouldn’t be worried, but the more I read about insulin resistance and metabolic syndrome the more worried I became. I wore a CGM and figured out what was happening. My glucose was down to 70 mg/ml at 4 am, but it would rise to 102 mg/ml by 9 am, when my blood was being drawn, even while I was fasting. My dawn phenomenon was exaggerating my fasting blood glucose much more than expected. I don’t worry about it anymore. Get a CGM and see if you have the same issue I have. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 7:15pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/10 "2025-04-21T19:15:44Z")
Thanks for the useful info, guys. That’s especially interesting about the “dawn phenomena”, which it sounds like you both experience. My mental model of glucose was that it sort of monotonically decreased after the last meal until it hits some steady state, but I see that’s clearly wrong–it can go down and up fairly dramatically even in a fasting period. Both my readings were taken just after noon, which for me is “dawn” since I wake up around 11. I ordered the Dexcom Stelo. Comes in a 2-pack; I’ll use one now and save the other for an experiment 6 months or a year from now, depending on the shelf life. Not particularly opposed to finger pricks but the Dexcom isn’t that expensive and it can give me 2 weeks of data without much inconvenience. > [@LSLGuy](#): > > “Ehh, who cares? More Pizza! More beer!!” I drink very little; probably a long-term average of 1-2 a month. Pizza isn’t uncommon, though. A typical meal is half a homemade pizza. I know what goes into it so it’s easy to estimate calories. 455 cal for 1 c of flour, 90 cal for oil, 12 cal for sugar, 480 cal for 6 oz cheese, 65 cal for 3 oz sauce, and 210 cal for 1.5 oz pepperoni. 1312 cal total, which is a tad under my BMR figure. Maybe 600 of that is carbs. Doesn’t seem too bad? Only about 45%. I don’t go out of my way to avoid carbs but I’m not the type to eat a giant plate of pasta with breadsticks on the side, wash it down with soda, then have a dessert later. Really I have very little sugar. Protein+fat tends to dominate my meals with carbs being there to hold things together (bun, tortilla, etc.). ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 21, 2025, 7:34pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/11 "2025-04-21T19:34:21Z")
I rarely eat more than 1 _bite_ of bread or bread-like substance at a meal. Two is objectively too many and will blow my BG through the roof. And zero bites is far better than one bite. Ordinary white wheat-based flour is really no different than plain white sugar to a diabetic. Neither is white rice. It’s all pure concentrated sugar as far as your pancreas can tell. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 7:40pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/12 "2025-04-21T19:40:22Z")
Fair enough. Well, I’m interested in what the CGM says. I just set up the app and it says the target for a non-diabetic is spending 96% of the time between 70 and 140. So there’s some allowance for short spikes, but it seems in line with what you said, that the damage is basically the integral of the time spent at high levels. ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 21, 2025, 7:42pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/13 "2025-04-21T19:42:30Z")
> [@LSLGuy](#): > > FWIW, late onset diabetes is a disease where you slowly burn up your pancreas by forcing it to overwork. Eventually as it wears out and dies off what’s left can’t handle the needs of your daily living and then the trouble really begins. The opportunity for early warning is not when your A1C starts rising, but rather when your post-prandial BG spikes are larger and last longer than they should. That’s the sign of a pancreas running flat out and not keeping up; taking 3 hours to do a 1 hour job. And those extra two hours of sprinting are what’s killing it. So your goal is to find out if you’re making it sprint, then if so, stop that through diet, exercise, weight loss, and, if necessary, meds. Like your heart, it can jog along 70 years no problem. Just don’t make it sprint several hours a day. Someone correct me if I’m wrong, but I don’t think the beta islet cells always die, I think they sometimes just go dormant. There is some preliminary research showing ways you can make the beta islet cells come out of dormancy and com back to life though. 1. Lose enough weight that you remove the visceral fat in your pancreas. Visceral fat (the fact that accumulates inside your torso and inside your internal organs) is the fat that causes metabolic health effects from obesity. > **[Remission of Human Type 2 Diabetes Requires Decrease in Liver and Pancreas...](https://www.sciencedirect.com/science/article/pii/S1550413118304467)** > > The Diabetes Remission Clinical Trial reported return and persistence of non-diabetic blood glucose control in 46% of people with type 2 diabetes of u… 1. Certain drug combos may be able to reawaken dormant beta islet cells or increase their proliferation. Medications like GLP-1 agonists, TGF-beta inhibitors and a DYRK1A inhibitors all can help create new beta islet cells. > **[Diabetes-reversing drug boosts insulin-producing cells by 700%](https://newatlas.com/medical/diabetes-reversing-drug-boosts-insulin-producing-cells/)** > > People living with diabetes might have a new hope. Scientists have tested a new drug therapy in diabetic mice, and found that it boosted insulin-producing cells by 700% over three months, effectively reversing their disease. [Inhibition of DYRK1A and GSK3B induces human β-cell proliferation | Nature Communications](https://www.nature.com/articles/ncomms9372#:~:text=%CE%B2%2Dcell%20proliferation%20induced%20by,regulators%20of%20%CE%B2%2Dcell%20proliferation). There is also research looking into creating beta islet cells with stem cells, then putting them in the pancreas. ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [April 21, 2025, 10:53pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/14 "2025-04-21T22:53:59Z")
I wore a CGM for 3 month last year. One thing you might want to investigate is eating order. Starting off with something high in fiber (but not bread), then fats and proteins, and starches and sugars last will slow down glucose metabolisation and blunt the spike. Another trick I learned for blunting the spike is a walk after eating. The OP says they are just curious, but the real value of the CGM is to help you visualize what your metabolism is actually doing and creating healthy habits based on that awareness. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 21, 2025, 10:57pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/15 "2025-04-21T22:57:29Z")
[Moderating] Since this is about the OP’s actual numbers, rather than a hypothetical, I’ll move it to IMHO as medical advice. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 11:09pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/16 "2025-04-21T23:09:02Z")
> [@Elmer\_J.Fudd](#): > > The OP says they are just curious, but the real value of the CGM is to help you visualize what your metabolism is actually doing and creating healthy habits based on that awareness. Yeah, I’ll be running some experiments and taking notes. Check the usual routine but also see how different foods behave. Maybe even try the pure glucose test that **Wesley\_Clark** mentioned. I’m not strict about OMAD and sometimes have a banana earlier in the day, plus my coffee has some calories. So I’m curious what these things do as well. First question to answer is if there _is_ a spike. > [@Chronos](#): > > Since this is about the OP’s actual numbers, rather than a hypothetical, I’ll move it to IMHO as medical advice That’s fine, but I’m not really looking for _specific_ medical advice. More about what I need to learn about how fasting glucose relates to A1c, what I should expect to see from the CGM, etc. My numbers are driving my particular interest but any information about the mechanisms here are welcome. ---
**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\ **Post date:** [April 21, 2025, 11:15pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/17 "2025-04-21T23:15:14Z")
> [@Dr.Strangelove](#): > > More about what I need to learn about how fasting glucose relates to A1c, what I should expect to see from the CGM, etc. Nothing in my case. I improved my Fasting Insulin from 16.9 ulU/mL to 8.1 ulU/mL in just two month using the CGM, but my A1C was the same (5.5%). ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 21, 2025, 11:45pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/18 "2025-04-21T23:45:08Z")
> [@Dr.Strangelove](#): > > Anything to concern myself with? No. Okay a bit more. Yes you are highly highly likely experiencing a mild “dawn phenomenon” but imagine worst case. You actually are at “prediabetes” level. What should you do? Eat a healthy diet and exercise regularly. What should you do if you do not have “prediabetes”? Eat a healthy diet and exercise regularly. In neither case is lots of pizza and beer the preferred course. And conveniently you _are_ eating a healthy diet. Sounds like. If you don’t exercise you should. Include some strength training. If you were going to persist as a worried well you could set an alarm and do a single finger stick at 3am, clearly enough time to be considered fasting after a 7 pm dinner. Odd are high that is under 100, I’d WAG under 90, and no need to mess with the CGM. We really have too much data sometimes. Especially the CGM of people without diabetes. We have no convincing studies about what ideal should be. Many will pathologize normal glucose swings. And CGM in those well are not very reliable: > **[Researchers warn continuous glucose monitors can overestimate blood sugar levels](https://www.bath.ac.uk/announcements/researchers-warn-continuous-glucose-monitors-can-overestimate-blood-sugar-levels/)** > > University of Bath study warns CGMs can prompt harmful dietary changes and distort perceptions of health. More testing is not necessarily better. It is sometimes. But sometimes very much not. Eat healthy. Exercise. Done. ---
**Author:** ![ThelmaLou](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thelmalou/32/390_2.png) [@ThelmaLou](https://boards.straightdope.com/u/ThelmaLou)\ **Post date:** [April 21, 2025, 11:54pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/19 "2025-04-21T23:54:59Z")
> [@Dr.Strangelove](#): > > Anything to concern myself with? No. Not with a fasting BG of 103 and an A1c of 5.2. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [April 21, 2025, 11:56pm UTC](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292/20 "2025-04-21T23:56:03Z")
> [@DSeid](#): > > If you were going to persist as a worried well you could set an alarm and do a single finger stick at 3am I’m typically still awake at 3 am 🙂 . I’m not a worrier, but I do like to track down oddities. “Dawn phenomenon” sounds like a perfectly reasonable explanation, and even if the CGM isn’t too accurate in an absolute sense, it should still be able to tell me if that’s what’s going on. Especially since I have a couple of lab data points to compare against. Maybe I’ll get a standard glucometer as well to compare against. They’re pretty cheap. [Next page](https://boards.straightdope.com/t/is-there-a-risk-to-slightly-elevated-glucose-with-normal-a1c/1017292.md?page=2)