Thursday, August 05, 2010

"Pre" but not Easy

I've seen several discussions recently in the Diabetes Online Community recently about the notion of "pre diabetes", a situation where a patient has blood glucose levels that are abnormally elevated without meeting the diagnostic criteria for Type 2 diabetes. Mike Hoskins wrote a thoughtful post about it not long ago, and it was discussed in the second Diabetes Social Media Activism session. It's come up one or two other times, as well.

By and large, the people I've seen weigh in don't care for it, either as a term or as a concept. And I have to say that I disagree, at least in regards to the concept. This post relates pretty heavily to yesterday's post about "reversing" Type 2.

The Analogy

I've seen a number of folks who argue against the notion of pre-diabetes by drawing an analogy to pregnancy. You can't be pre-diabetic, and you can't be a little bit pregnant. Once you're pregnant, you stay pregnant until the pregnancy is interrupted in some way or the baby is born. According to the analogy, either you're diabetic or you're not, and once you're diabetic you're always diabetic until death or such time as there's a cure.

In pregnancy, there is a pretty well-defined beginning, to the best of my layman's understanding: an ovum is fertilized by a sperm cell. It may be that the onset of Type 1 diabetes is comparable, if onset is considered to occur when the immune system starts trying to kill off the pancreatic beta cells. So, it may be that the pregnancy analogy would work for Type 1. (It's also a distasteful analogy, in my mind. Comparing the prospective birth of a child to a disease state? Really?)

But what's the analogous is/isn't point in Type 2 diabetes? Is it when insulin resistance rises above a certain point, and how wold this be measured? Is it when the observable measure of fasting blood sugar rises above a certain level, or a certain A1c, or a certain result from a glucose tolerance test? Is it when the ability of the pancreas to supply insulin begins to be impaired, through a mechanism that I don't believe is yet understood?

And, do we really know that no one who meets whatever criteria you choose ever stops meeting that criteria?

Ironically enough, I think the case against the pregnancy analogy ultimately falls when we consider gestational diabetes. Some significant percentage of women develop insulin resistance during pregnancy and need to be treated with oral medications or insulin. When the pregnancy ends, so does the diabetes. A woman who's had gestational diabetes is at significant risk of later developing Type 2, but for many the diabetes goes away and stays away.

The pregnancy analogy just doesn't work for Type 2.

The Concept

The next point I want to consider is whether the concept of pre-diabetes is meaningful or not, temporarily laying aside the choice of term. It may be that further research will allow us to dump it entirely, if the diagnostic criteria for T2 can be refined such that a patient is considered diabetic at one level (of whatever we're measuring), and those folks below that don't need to worry. But, given what we think we know now, this seems counter-intuitive.

As I discussed at length yesterday, there does seem to be a stage early in the development of T2 when lifestyle interventions may arrest the progression of the disease and development of symptoms. It makes sense to me that there would be a stage where there's sufficient insulin resistance to cause blood glucose levels to climb but precede (it is to be hoped) much in the way of damage to the pancreas' ability to produce sufficient insulin.

(Mike, in his post linked above, describes an experience his wife had being "diagnosed" with pre-diabetes in a health fair. It would be my hope that, if such a fair showed elevated blood glucose levels, the patient would not be "diagnosed" but rather encouraged to visit their physician for possible further testing and perhaps intervention.)

If there IS such a state, if significant lifestyle change can stop disease development (possibly for a lifetime), it seems to me that physicians have a strong obligation to watch for it. And there's another thing: we're used to Type 2 progressing pretty slowly, but that's not the case for everybody. A patient who doesn't quite meet diagnostic criteria at one checkup may, I'm guessing, come to the next checkup complaining of foot pain and blurred vision.

The Term

So I'm a fan of the concept of pre-diabetes, at least until it's shown not to be useful in helping people be as healthy as possible. However, I don't much care about the term itself. I don't doubt that there would be good candidates, and I'd be happy with any of them if the support for it is broad enough to minimize confusion.

So, if you hate the term, I'm not going to argue with you. If you hate the concept, though, I'd ask that you give the idea another look.


  1. A lot of the recent research indicates that the changes start occurring years before D actually manifests itself. The UK Whitehall II study released last summer comes to mind. I think the term "pre-diabetes" is just fine and can give people a chance to make lifestyle changes as soon as they possibly can

  2. Thanks for the post and shootout, Bob! Good insight and thought-provoking, as always. As far as the "pre-diabetes," I'm not a fan of the term or the concept. You make a good point about the pregnancy argument applying to T1, but not T2. That makes sense, as the lines are less clear and obviously can change significantly at any time, going back and forth. But I still believe that it's a shoddy term and concept because any non-D is ALWAYS a "pre-diabetic," as they ALL face potential risks of developing diabetes if not being as healthy as they should. It's a fear-mongering concept, in my eyes, to be able to tell people "I told you so" in fact they do develop diabetes down the road. But again, this all from a longtime Type 1 - so I'm biased. And a little nuts, too.

  3. Mike, it's not really true that all non-Ds are pre-d, because of the genetic component. No T2 genes, no T2. So perhaps rising numbers is (or ought to be) a signal that, "Dude, all the pieces are in place. Whatcha gonna do about it?"

    I certainly agree that there's a fair amount of fear mongering happening, some of it well-intentioned (if flawed) and some of it just snake oil. But that doesn't mean that we can ignore the potential for helping people.

  4. I like the concept of pre-diabetes, just don't like the fact that there really seems to be no standard. What one doctor considers pre-diabetes, another considers T2. Granted, the same argument can be made for when to start insulin for T2 (a completely different subject). But pre-diabetes, to me, would mean that your sugars are starting to be elevated and diet and exercise should be monitored. Yet, I have seen people state they've been told by their doctor that they are "pre-diabetic" and they're taking pills and testing their sugars, etc like other T2's. Yet, those are also the same people who feel their Diabetes isn't "bad" enough to require insulin. In that respect, I feel that it's like saying they're a "little bit pregnant".

  5. AngMy, I certainly wish that the standards were more clear and that health professionals who work with diabetics were up on current diagnostic standards and the standards of care. I wish that for diabetics of all types. I've heard too many stories of doctors that didn't seem to be up to date and thus unable to provide diabetic patients with the best care.

  6. A few months ago, I went through the same set of issues. What I came up with is a progression index similar to those used in diagnosing and treating hypertension (and prehypertension) and cancer.

    In the case of "prediabetics" on pills, there have been some studies which indicate that prescribing metformin to people whose blood glucose levels consistently range higher than "nondiabetic normal" but not so high as to be diagnosed "diabetic" -- especially when other components of metabolic syndrome (overweight/obese, hypertension or prehypertension, high cholesterol) do improve insulin sensitivity, drop weight, and in general improve their physiological benchmark numbers (per current benchmark guidelines).

  7. My understanding of the literature is that one in four prediabetics progresses to diabetes over the next 3-5 years, if nothing is done.

    That's a high risk.

    Prediabetes has been much more useful clinically than the old "borderline diabetes." Compared to prediabetes, it's a lot easier to ignore "borderline diabetes." And that's a mistake.


  8. Bob - At least we can agree to disagree. This is where the American Diabetes Association needs to provide more definitive guidance. We also must consider that a persons ethnic origin also determines the point of deciding whether a person has diabetes.

    Too many doctors do not use due diligence in explaining and educating their patients about how serious they should be about "pre-diabetes" We are fortunate that many patients do take it serious, but too many just figure that they can continue as is for the time being. The doctors need to reread the Hypocratic Oath when it comes to diabetes and not do the harm many are doing.

    Even though I use the term, I do not like it not the concept. There has to be a better method.

  9. Great, thought (and comment) provoking post. I haven't decided yet where I stand on the issue. I'm just going to stand back a bit and listen to all of you smart people talk about it some more...


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T Minus Two by Bob Pedersen is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.