Posted on 07/02/2009 12:12:52 AM PDT by neverdem
NEW ORLEANS — An international committee of experts has endorsed the use of the hemoglobin A1c assay to diagnose diabetes, at a level of 6.5% or above.
The 21-member international committee, chaired by Dr. David M. Nathan, was appointed by the American Diabetes Association (ADA), the European Association for the Study of Diabetes (EASD), and the International Diabetes Federation (IDF). Their consensus report—presented in a symposium at the annual scientific sessions of the American Diabetes Association and published simultaneously online in Diabetes Care—has not yet been officially endorsed by the three organizations.
“This is the first major departure from the way that we've been diagnosing diabetes for more than 30 years,” Dr. Nathan, director of the diabetes center at Massachusetts General Hospital and professor of medicine at Harvard Medical School, Boston, said at a press briefing held during the ADA meeting.
Since 1997, the cut-offs for diagnosing diabetes with either the fasting plasma glucose (FPG) or the 2-hour oral glucose tolerance test (OGTT) have been based on the risk for developing retinopathy. The committee reviewed available data and determined that the HbA1c assay was a better measure of that risk for several reasons.
HbA1c is a more stable analyte than is glucose. And importantly, HbA1c is more convenient as it does not require an 8-hour fast or a test that takes 2 hours. “It also correlated very tightly with the risk for developing retinopathy,” Dr. Nathan said.
The panel also advised that people with HbA1c values between 6.0% and 6.5% be considered at high risk for diabetes. However, they said that the term “prediabetes” is misleading because not everyone who meets those cut-offs will progress to diabetes, and some who are below the cut-offs will.
The document is only a consensus statement at this point, Dr. Paul Robertson, ADA president, emphasized. The ADA will now refer the paper to a practice group, which will review it to determine the medical, social, financial, worldwide, and other implications for changing the diagnostic criteria for diabetes, said Dr. Robertson, professor of medicine at the University of Washington, Seattle.
The document specifies the following for the diagnosis of diabetes:
▸ Diabetes should be diagnosed when HbA1c is at least 6.5%. Diagnosis should be confirmed with a repeat HbA1c test. Confirmation is not required in symptomatic subjects with plasma glucose levels above 200 mg/dL.
▸ If HbA1c testing is not possible, previously recommended diagnostic measures such as the FPG or 2-hour OGTT are acceptable.
▸ In children and adolescents, HbA1c testing is indicated when diabetes is suspected in the absence of both classical symptoms and a casual plasma glucose concentration above 200 mg/dL.
For the identification of those at high risk for diabetes:
▸ The risk for diabetes based on levels of glycemia is on a continuum. Therefore, there is no lower glycemic threshold at which risk clearly begins.
▸ The categorical clinical states of prediabetes, impaired fasting glucose, and impaired glucose tolerance fail to capture the continuum of risk and will be phased out.
▸ The HbA1c assay has several advantages over laboratory measurements of glucose in identifying individuals at high risk for developing diabetes.
▸ Those with HbA1c levels below the threshold for diabetes but at least 6.0% should receive demonstrably effective preventive interventions. Those with HbA1c below this range may still be at risk and, depending on the presence of other diabetes risk factors, may also benefit from prevention efforts.
▸ The HbA1c level at which population-based prevention services begin should be based on the nature of the intervention, the resources available, and the size of the affected population.
“To much of the medical community of America, this will not come as a surprise,” noted Dr. Richard Kahn, chief scientific officer of the ADA. “Many physicians are already using HbA1c with their own cutpoints for diabetes.”
Thanks for the ping, neverdem!
speaking of A1c...found this on Quest Diagnostics’ website: http://ir.questdiagnostics.com/phoenix.zhtml?c=82068&p=irol-newsArticle&ID=1295061&highlight=
Thanks, BFL
If you can’t get the numbers you want, you change the way you get the numbers. Sounds like a SHELL game. I know I have been going through this the last 15 years. You can not make MONEY if the numbers are to low.
Exactly. If you do some research, you'll see that they've recently lowered the numbers and now that allows them to give you a diagnose of a "high sugar" reading from that lowered threshold.
I think I also read somewhere that Canada uses a different threshhold.
I don't trust any of them.
You are, of course, free to be suspicious but more than half the diabetics in the country have not yet been diagnosed so the doctors should easily make up for you absence.
Apparently you did not read the article. The piece describes how different tests results can be interpreted to make a reasonable determination of a threshold.
The A1C has been used as a reliable indicator by my doctor as a reinforcing factor. This piece now reverses the order. The A1C becomes primary with the sugar level as a solid backup.
Do you know your A!C level?
Has it been determined?
If not, you are likely not at risk
Why? I’ve long criticized the futzing with the numbers - and this change is worse, to me.
instead of sticking with an inexpensive, instant test (plasma glucose), they have shifted toward a much more expensive laboratory test that is typically not administered unless sugar problems are at least suspected. How much money did the panel receive from the med lab industry?
The HbA1C gives inferential evidence of an average blood sugar. Therefore, they are endorsing the idea that a balance of high and low-sugar spikes is NOT diabetes? I vehemently disagree with this decision!
Think about this: The HbA1C can be “fooled” by semi-balanced highs and lows. The test is a measure of control, not variation. To me, diabetes is characterized by the variation in sugar levels.
I’m not a doctor, just a diabetic engineer. BUt I can’t say I agree with this push (much the same as I still disagree with the fundamental redefinition of the “diabetes” blood glucose ranges several years ago).
No I don't, and no it hasn't.
The way my Dr explained it at first is that you (the patient) can futz the blood glucose number temporarily. The A1C will tell him how I am doing over a longer period of time—making longer term management more effective.
I still measure a couple of times a day because I need that constant metric to make sure I don’t slip off the wagon.
Whatever works to keep it down is what I favor.
Yes, the daily numbers can be futzed. The two tests are complementary, in fact. My most recent HbA1C is helping to correct an issue with over-medication using insulin (it’s a long story).
However, it appears to me that they didn’t catch enough people with their plasma glucose range shift a few years ago, so they’re introducing a new way to spread the net. This way, they also include the med labs (or test kit providers) in the bonanza, too.
Yes - I’m cynical about “latest medical science”. I remember the “egg/no egg” back and forth all too vividly not to be skeptical.
Newly diagnosed diabetic (A1c of 10.9).
I am an opinionated, brash, sometimes loud-mouth (i.e.: engineer) who has been diabetic for almost 13 years now (HbA1C 6.6 in May).
Control is the name of the game. Are you type I or II? (None of your business is a valid answer, BTW.)
I’m type II, but now on insulin due to lack of control or decaying insulin production (probably lack of control - honestly).
Diabetes is considered a continuum, not a series of isolated events. Considering that all knowledge is to a degree imperfect, the A1C has been accepted as the best way to grasp the state of the continuum
I only have to get the A1c once a quarter, and my Dr doesnt even WANT me to take daily readings (I am very early in the process.)
The labs seem “reasonable” and he is not someone to run around prescribing a lot of tests. I don’t have a huge amount of reference in this. Are people getting the A1C more often than that?
While I agree with the A1c approach, the sticky part comes in with picking the target number.
As an example, blood pressure of 120/80 was considered ideal. Now it’s 115/75. I wonder how much input the pharmaceutical companies had on the new target?
The same can be asked with recommended cholesterol levels. If they’re not selling enough Zocor/Lipitor, then lower the target numbers.
As far as I know, once per quarter is the norm. I have it every 3-6 months.
The average always downplays the extreme. Statistically, an average without contextual “swing” information is nearly meaningless.
I do not yet see exceptional merit in the reasoning behind this change. I do see powerful monetary reasons to suspect the decision.
BTW, to say that the A1C “has been accepted” when the change has just been proposed is premature, IMO.
......“has been accepted”......
ok, I’ll concede that statement as too specific.
My personal physician made the diagnosis after watching the fasting glucose results for a while. He than introduced the A1c and it now seems to be the primary number in spite of considerable variance in the fasting glucose.
I think perhaps your fixation on cost is misplaced because to obtain a continuous data stream, it is necessary to record fasting sugar daily and plot a curve. Then take the curve and plot a moving average. Why bother? The A1C does the job nicely while eliminating a lot of bother and other tests.
This is especially true for those of us at the low end of the numbers.
I was able to rely more on the HbA1C before I started insulin. I need the instant feedback to control dosage, in part.
My fixation on cost isn’t the consumer end, but rather the producer end. I’m afraid I have become fairly jaded regarding the incidence of monetary considerations infecting legal and medical decisions. Honestly, I would be surprised if there wasn’t lobbying for this outcome by the HbA1C labs or test kit makers. After all, some of the biggest proponents of the child-safety-seat laws (now up to 8 years old in some places!) were the child-seat makers.
In my industry (safety critical software), the small, in-process verification steps are complementary to the larger, milestone steps. I see the daily (or more often) plasma glucose reading as the self-check, with the HbA1C as the higher-level check.
Oh, wow - high numbers. Mine was taken in March and came in at 7.6. I had to insist on it being taken, and that was how I finally got my doctor’s attention.
Five years ago, at age 65 and after 3 years of progressive loss of feeling in my feet, and my Dr always instructing me to fast before each appointment, my A1c was about 7.5 - although my fasting glucose was normal. He never did a glucose tolerance test.
He handed me a copy of a “diabetic diet” brochure and a prescription for a meter, along with instructions to just monitor my glucose for a week. I learned that non-diet soft drinks, sweet & sour pork over a small mountain of rice, or a loaded baked potato sent my glucose above 240. Bread and pasta also raised it, but not as much.
But the diabetic diet seemed to emphasize carbohydrates! So after some research I settled on a pretty informal low-carb diet - except for various fruits - which I have adhered to ever since. My glucose averages under 100, measured morning and night, and my A1c is back to 5.5.
Am I diabetic? I still have peripheral neuropathy, and my opthalmologist has found early cataracts in both eyes, as well as early “low-tension” glaucoma that I am treating with eyedrops. And when I drank a mint julep (sugar syrup and bourbon) last Derby day at my wife’s UofL alumni party, my glucose paid another visit to 200+!
This can be very dangerous and mislead a person who is on a sugar roller coaster that he is doing OK when he is not.
I know the problem well... I’m trying to recover from it right now.
The a1c has been the bell-weather of control since it became available.
The bottom line is this: Most of us know when we're doing something to make the situation better or worse. I don't need a meter to tell me that the hot dog I just ate on that sweet, white bun is going to cause a big jump in my BG for a couple of hours.
Further, my fasting BG is going to be dependent on how I treated myself yesterday.
I am not arguing against the HbA1C test by any means. I am simply stating a truth - that the A1C can be fooled, just like any other test, including plasma glucose tests.
I am also questioning the motivation for the change in test standard, as well as any modification to the range of numbers that are considered to be diabetic. That’s not a refutation of the science.
I will retract my criticism of the HbA1C test just as soon as someone can prove it isn’t possible to foll it (which necessarily includes re-diagnosing the issue I am dealing with now, along with my doctors). Until someone can refute the truth, my criticism stands.
As do my questions regarding motivation.
I don't understand. Are you saying it can be manipulated in some way? Something along the lines of: If a perfectly healthy athlete munches on gummy bears all day it will result in a higher a1c?
HbA1C is an average (a “mean” in statistics). There is a companion piece of information used in statistics called a “standard deviation”, which indicates the variability of the data sample. The HbA1C does not provide any way to measure the standard deviation, which means that wild gyrations cannot be accounted for.
The average value for the data set {48, 49, 50, 51, 52} is 50.
Similarly, the average value for the data set {10, 20, 50, 80, 90} is 50, but the standard deviation is over 35 (as opposed to 1.58 for the other data set).
2/3 of all data values are expected to fall within one standard deviation of the mean. 98 or 99 percent of all values are expected to fall within two standard deviations of the mean. The variability of the second data set means that the average value is unreliable for predicting any particular instantaneous value.
Now, with respect to blood sugar, consider that non-diabetics are expected to have a low variability in their sugar readings. Therefore, the HbA1C’s ignoring the variability is of no real concern.
But a diabetic who varies wildly around a “normal” mean value will be shown by the same HbA1C test to fall within the expected range - thereby missing the diagnosis. Because of the variability, the instantaneous reading is a better option for diagnosing the issue.
That’s what I meant by “fooling” the test - the fact that highly variable data can invalidate the outcome. My recent 6.6% reading (approximately 158 mg/dl average) directly conflicts with the 205 mg/dl fasting sugar average (with a standard deviation of 45). In fact, the HbA1C fell below the range in which two-thirds of all of my sugar readings are expected to fall - and this was the fasting sugar.
That means that I was experiencing wild swings around a high but relatively benign sugar reading. With some of the numbers I was seeing, I had to be going seriously low at least once a day.
The bottom line to me is that an average without variability info is incomplete data. There may be mitigating factors due to the biology of the situation, but I’m not convinced this is the best route forward.
Of course, I’m just one guy expressing his opinion, too! ;-P
As a result; they can dupe even more people into consuming even MORE high-priced 'medication'. Quit eating garbage, America...bye-bye, Type 2.
Five years ago, at age 65 and after 3 years of progressive loss of feeling in my feet, and my Dr always instructing me to fast before each appointment, my A1c was about 7.5 - although my fasting glucose was normal. He never did a glucose tolerance test.
He handed me a copy of a “diabetic diet” brochure and a prescription for a meter, along with instructions to just monitor my glucose for a week. I learned that non-diet soft drinks, sweet & sour pork over a small mountain of rice, or a loaded baked potato sent my glucose above 240. Bread and pasta also raised it, but not as much.
But the diabetic diet seemed to emphasize carbohydrates! So after some research I settled on a pretty informal low-carb diet - except for various fruits - which I have adhered to ever since. My glucose averages under 100, measured morning and night, and my A1c is back to 5.5.
Am I diabetic? I still have peripheral neuropathy, and my opthalmologist has found early cataracts in both eyes, as well as early “low-tension” glaucoma that I am treating with eyedrops. And when I drank a mint julep (sugar syrup and bourbon) last Derby day at my wife’s UofL alumni party, my glucose paid another visit to 200+!
The confusion in the Medical field was rampant. Most doctors then thought you treated Type I and Type II the same way: Insulin. I sensed the confusion and did the research. I had two Doctors prescribing Insulin and an ADA diet with lots of carbohydrates. I feel the L-rd led me to a Christian Doctor who used Ha1c I was able to stop the Insulin and take Glucophage( Metformin ), diet and exercise. I bought a Bowflex and began serious resistance training. I began to do two Protein drinks and one meal a day. My Ha1c dropped to below 5. Later, I sold the Bowflex. My wife and I began an Atkins diet and my BS dropped 100 points in three weeks. My drink of choice now is Dalwhinnie over shaved ice, I, like you, was diagnosed as a Type II Diabetic fifteen years ago when I was fifty-five.
shalom b'SHEM Yah'shua HaMashiach
and had been made aware of Metabolic Disorder with a Dr Ron Rosedale.
Recently my feet began hurting, I started daily testing: BS of 240.
Palin Settles on Hemoglobin A1c to Diagnose Diabetes: Implications of the shift to be assessed.
This will be good because it won’t just be the bloodsugar reading at the time but the average of what it has been for the last 8-12 weeks.
My Dr. here in town has been using that for several years now. :)
They lowered the number to 6 because damage begins to happen to the body if the numbers tun over 6.5 for very long. How is more research a bad thing?
My last one was higher than it’s been in a while and it was 6.0. Need to get it back down into the 5.5 and under range.
.....I am an opinionated, brash, sometimes loud-mouth....
Yes, but are you educated?
Im a type 1 of nearly 40 years (I’m 48). I test 4 times a day and take insulin before each mean and a long acting at night. Last A1c was 6.0 first time in 2 years I’ve had one that high. Am curently working on getting insurance to pay for both a pump and a contant glucose monitor for even better living.
That depends - does a compulsive need to understand things mean I educate myself?
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