In part 1, I talked about the potential switch to the A1C test for the diagnosis of diabetes, in particular, type 2 diabetes. Now, I want to talk about what changes to the diagnosis of diabetes might mean for diabetes treatment.
A quick refresher, if using the fasting plasma glucose test, a value of less than 100 is considered normal and a value of 126 or higher indicates a value in the diabetes range. A value in between the two has been labeled “impaired fasting glucose,” and by some, “prediabetes.” The A1C test doesn’t have a range that is considered “prediabetes,” the proposed cutoff values would be 6.5 % for a diagnosis of diabetes, and 6.0% as normal, with that gray zone in between currently unnamed.
People inside and outside of the medical community expressed scepticism about prediabetes, whether it really meant people with that label were truly at increased risk of developing diabetes. Was it an “early warning sign,” or a “window of opportunity?” Or a scare tactic? If it was an early warning sign, sometimes it felt like the signs being posted in the prediabetes range read “one way,” or “Abandon hope, all ye who enter!”
According to the CDC, “People with prediabetes are 5-15 times more likely to develop type 2 diabetes than are people with normal glucose values.” This doesn’t mean that 100% of people with prediabetes will go on to develop type 2 diabetes, and it isn’t a one-way street, people are able to go from having impaired fasting glucose to normal glucose. Higher than normal glucose values that never develop into diabetes may lead to other problems, such as heart disease and stroke, or may not develop into anything.
Here’s what the CDC says about progression from prediabetes to diabetes (see the source page for references):
“The natural history of prediabetes (both IGT [impaired glucose tolerance] and IFG) indicates that about 25% of persons with prediabetes progress to diabetes within three to five years. With longer observation, the majority of individuals with IFG or IGT go on to develop diabetes within about 10 years, unless they lose weight through moderate changes in diet and physical activity. Over the course of a lifetime, as many as 83% of persons with prediabetes (IGT) who neither lose weight nor engage in moderate physical activity will develop diabetes. Over the course of a lifetime, approximately 65% of persons with prediabetes who lose weight and engage in moderate physical activity will go on to develop diabetes.”
What this says to me is that some cases of diabetes can be delayed, and some can’t. I think that there isn’t “type 2 diabetes” but there are “type 2 diabeteses” — more than one type of diabetes. Each of us with diabetes (or the tendency to develop it) responds to different treatments and therapies. Sure, some things do seem to work for most people with type 2 diabetes, but as commentator (rainbow?) Hairy Legs pointed out, not even the proposed standard test works for everyone.
If the point of diagnosing people with prediabetes is to take advantage of the “window of opportunity” so people can make changes to avoid the onset of diabetes, a test that was better able to predict which ones will go on to develop diabetes would be a good thing. What the A1C test can do is tell what blood sugar levels have been doing (at least if the test works for the individual, as Hairy Legs points out) for the past 2-3 months, not just at that one point in time. But does a value of 6.2% mean an inevitable progression to type 2 diabetes?
For the record, while I consider weight loss as a goal to be futile, unnecessary and counterproductive, each of us also has the right to experiment with physical activity and which foods help us feel good to figure out what feels right for us. If a piece of information about our health helps us make choices that are in line with our personal goals, and a person wants that information, it can be a helpful thing. But using the threat of diabetes to bully people into losing weight or to prevent them from gaining weight is outside of my interpretation of the ethics of my profession.
With this “unnamed zone” between normal A1C levels and diabetes levels, what will health care providers* tell people who have an A1C higher than 6% but lower than 6.5%? Will it sound like this?
Provider: Your A1C is 6.3%.
Person: What does that mean?
Provider: You are on your way to developing diabetes… maybe. Or maybe you already have diabetes. It’s hard to say.
Person: What should I do?
Provider: Lose weight and exercise. Oh, wait, it says here that you already exercise, and losing weight doesn’t seem to be successful for you, or anyone else, really. Want some metformin?
Person: Will that keep me from getting diabetes?
Provider: Hard to say. It might delay it for a while. Exercising is good. So do that. We’ll check your A1C level again.
Person: How soon?
Provider: I’m not sure. Not before three months have past. Are you sure you don’t want any of this delicious metformin**?
Depending on the frequency of screening with the A1C test, there may be more or fewer people with diabetes who are caught earlier in the progression of the disease, which I regard as a good thing. But the conversation between health care provider and person sitting in front of them for those with an A1C of 6.5%-7% might look really similar to the above conversation.
I was hoping in writing this to cover a bit more ground, but there are many unknowns. What is know is that diabetes is quite possible to control. I don’t wish it on anyone, but I also know that I’ve been able to manage it pretty well. I have been extremely fortunate to have great doctors (and some not so great ones, but that’s for another post) and, for the most part, good health insurance. I know that isn’t the case for everyone, and it makes a big difference.
* I use “providers” because not everyone sees a doctor for their health care.
** Although personally, metformin works really well for me, there are many people who report the same side effects as Meowser.
What do you think about the A1C test being used to diagnose diabetes?
Angry Gray Rainbows 
“Delicious metformin,” hehehehe.
Like I said, I don’t have a problem with doctors trying the stuff out on people to see how they tolerate it; my problem is with what happens when patients say they can’t tolerate it.
And there are definitely people who think there are more than two types of diabetes. There’s a lot more research to be done, for sure.
From what I have seen of my husband’s A1c test results, I’m not sure it’s that good an indicator. DH has an A1c that is currently 6.3, but that’s an average of what his blood sugar has been over the last 3 months. Since I’m the one who writes down his readings when he tests, I see the spikes and the lows (his highest reading in the last 3 months was 257, his lowest was 75). From everything I’ve read, those high spikes are not good, and according to his doctor, he should be striving for blood sugar readings no higher than 160 and no lower than 70.
DH’s case manager said that when his A1c was 8.9, that meant he was having spikes as high as 300 (but I happen to know that some of his spikes were higher than that).
I would think that the glucose tolerance test would be a better indicator of diabetes, but even then, it’s not all that good, because how many people actually eat or drink something that is that sugar-laden (I know I don’t, that much sugar gives me horrendous heartburn)?
For myself, since my dad was diagnosed with diabetes when he was 72 (he’s 76 now) and my mother’s grandmother had diabetes, I test my blood sugar occasionally (I usually do a fasting test when I first get up, and then 1 hour, 2 hours, and 3 hours after a normal meal (and our meals are usually mostly protein, fats, and low-carb veggies, with minimal amounts of rice/potatoes/pasta. So far, my numbers run between 60 (fasting) and 120 (after meals), so I’m not worried. However, if my post-prandial numbers get higher than that, I’ll be asking my doctor to have that checked out.
I hang around at Jenny Ruhl’s site a lot, so when I realized I was having high post meal readings, I brought this to my Dr.’s attention. They decided to do a fasting glucose test, but the day I went in for it, my blood sugar was already “too high” to do the test. They sent me home. Because apparently, it was “too high” to do that test to tell if I could be diagnosed with diabetes, but not high enough to actually diagnose me with diabetes — that dreaded “IFG/IGT” zone. When I basically insisted on at least trying metformin (had to throw a temper tantrum) they put me on a 500 mg a day dose — which does pretty much nothing. I gather it needs to be up int he 1500ish range to really have an effect on some people. Anyways — my “diagnosis” is “Metabolic Syndrome”.. Metabo! So they want me on statins and they take my blood pressure incorrectly with the too small cuff and then try to give me blood pressure medication! I have been working at glucose control through diet, but I am losing the ability to do so. Since my A1c is 6.2, Dr. doesn’t feel it is necessary to do anything at this time. Evereyone says I should switch doctors. I have a referral to a new endo. We’ll see if that helps at all.
“But using the threat of diabetes to bully people into losing weight or to prevent them from gaining weight”
I only wish I had had more doctors who believed that… I was told that I was prediabetic as a bludgeon to make me lose weight for YEARS when my fasting blood sugar has never, as far as I know, been above 100 –back when I was testing it myself every day it was regularly 95.
Now, I know that someday I will be diabetic, because basically ALL the women in my family (both sides) are eventually (fat or thin) –and many of the men on one side, too. But it didn’t help that doctors were treating it like this horrible fate (seriously, like you get diabetes and then you wind up blind and in a wheelchair and then you die a horrible death) that I was going to doom myself to if I didn’t Lose Weight NOW!
Ahem. Sorry about that.
Even now, my new GP seems … puzzled by my (hard-won) attitude of not being afraid of becoming diabetic. (I fired my endo for, among other things, acting like the side effects I was getting from the amount of metformin she had me on were a GOOD thing because “you’ll eat less”. And therefore lose weight.)
What do I think? That it’s a way to label more people as at risk for diabetes and targeted for medical intervention. Blood sugars are more measures of diet than of the biological aberrations that are the disease process of diabetes.
The CDC is hardly a source of credible information on a lot of things — look at what it tells us about obesity. Endocrinologists have widely published research showing that just as many people labeled as prediabetic go on to develop diabetes as not — it’s not credible. The cut-off is mostly a measure of aging (the single largest factor after heredity). The cut-off used to be 146.
There’s also no credible science behind claims that any particular diet or lifestyle can prevent or delay the actual disease of diabetes.