Posted on 04/05/2009 8:19:05 AM PDT by neverdem
The way that diabetes is diagnosed in the United States is about to change.
Later this year, an expert panel organized by the American Diabetes Association will issue a report making blood level of glycosylated hemoglobin (HbA1c) an accepted method for diagnosing diabetes, according to staffers from the ADA. Although the decision is not yet finalized, “the group will likely recommend [HbA1c] as the preferred test,” placing it above the current diagnostic standard (the fasting blood glucose level) and also above the historic criterion for diabetes diagnosis (the glucose tolerance test), said Dr. Sue Kirkman, the ADA's vice president for clinical affairs.
The report from the ADA's Expert Committee on the Diagnosis and Classification of Diabetes will also set the HbA1c cut point for diagnosing diabetes, but this value has not yet been finalized.
This shift on the use of HbA1c for diagnosis stands to legitimize the method that is already commonly used by many primary care physicians, said Dr. Mayer B. Davidson, an endocrinologist at Charles R. Drew University of Medicine and Science in Los Angeles and professor of medicine at the University of California, Los Angeles. He applauded the decision, noting that “HbA1c is a more valid way to look at what is going on with glucose,” compared with glycemia levels.
Adoption of HbA1c as the primary diagnostic method also stands to make the diagnosis of diabetes substantially easier than it has been up to now, meaning that more people will probably be tested and thus more people with the disease will be identified.
“Since the HbA1c test doesn't require fasting, the hope is that it will be more convenient and that more people will get tested and diagnosed early,” Dr. Kirkman said in an interview, noting that an estimated 25% of people in the United States who have diabetes are undiagnosed.
The Expert Committee on the Diagnosis and Classification of Diabetes is an ad hoc group that the ADA convenes when it “feels there is a need to revisit some area related to diagnosis or classification,” Dr. Kirkman said.
The current round of deliberations began last year, and the group was constituted not only with members picked by the ADA, but also with representatives from the European Association for the Study of Diabetes and the International Diabetes Federation. “Eventually it is hoped that all three organizations will adopt the recommendations so that there is a worldwide standard.” ADA officials think the report may be ready for release before or during the ADA's annual scientific sessions in June.
Making HbA1c an accepted diagnostic test—let alone the preferred test—has been on the table for years. In a recent talk at a meeting sponsored by the ADA in New York, Dr. William C. Knowler spelled out the case in favor of using glycosylated hemoglobin, as well as the shortcomings of this approach.
The strengths of HbA1c as a diagnostic tool include the following:
▸ A more standardized assay and substantially lessinterlaboratory variability, compared with measurements of blood glucose.
▸ Consistency in using the same assay for diagnosis that is also routinely used to monitor patient treatment and to predict the risk for long-term complications.
▸ A better index of overall glycemia.
▸ No need for fasting before the specimen is drawn.
▸ No effect from acute changes in levels of blood glucose, such as those caused by illness.
Another attraction of HbA1c is that when the level goes above 7.0%, it becomes strongly correlated with the development of microvascular complications, noted Dr. Davidson. “There is no absolute way to diagnose” diabetes. “Where we draw the line is somewhat arbitrary.” Basing diagnosis on a test that can reliably predict the risk for microvascular complications is attractive because these complications “are fairly specific to diabetes,” he said in an interview.
But relying on HbA1c for diagnosis also has limitations. A person's HbA1c level can be affected by hemoglobinopathies, variations in red cell turnover, and unexplained racial differences, said Dr. Knowler, chief of the Diabetes Epidemiology and Clinical Research Section of the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix and a member of the Expert Committee.
Perhaps most importantly, switching the diagnostic criterion will create a break from the past that might make it hard to reconcile old epidemiologic observations with new ones.
A similar break occurred in 1997, when the ADA switched its diagnostic standard from the blood glucose level 2 hours following an oral glucose challenge to a fasting blood glucose level. That switch resulted in a sudden spike in the number of patients diagnosed with diabetes, Dr. Knowler said.
The fact that an HbA1c cut point for diagnosis has still not been set highlights the controversy this issue generates. A cut point of 6.5% has “some useful properties,” he acknowledged, but 5.5% is “a level to raise concern” that a person is at risk for eventually developing diabetes. Choosing a cut point “is a complicated issue that depends on how harmful are missed diagnoses and overdiagnosis,” he said.
In contrast, Dr. Davidson, who is not a member of the current Expert Committee although he served on it in the past, leans toward a cut point of 7.0% because of its significance for microvascular disease.
I definitely should have mentioned that it’s a form of Thiamine, and is very safe.
It does sound exotic, doesn’t it.
I see A1C kits are available OTC now, but it is really difficult to get any blood out of my wife using the usual lancets, and I generally can’t do it. Even with the depth set at nearly the maximum there is only the tiniest trace of a droplet and not even enough for the fancy low requirement meters. I’m afraid the lancet tip is going to hit the bone if it goes any deeper. The forearm is hopeless — no sign of blood whatsoever. What do people do in a case like this? We have tried the usual heating the area, rubbing the area, etc., etc. OTOH, I gush with just a small prick when I have practiced on me. Maybe the answer is to fly up at 12,499 MSL and try for a sample? Perhaps at the bottom of a loop
??????
Me too, I thought it was the test they used for diagnosis!
Constant diarrhea mostly, for years. On Avandia, the muscle aches and weakness were severe. Junovia caused awful itching. So far, glyburide is the only thing that seems to have no bad reactions.
I think your doctor has it right.
The snow is melting. It's about time for us gray hairs to get the bikes back in service. It's +42F outside right now. Good enough to take the cruiser out for a bit.
So do I.
I was told about that but since I’m on an Atkins type diet, not experiencing it.
I eat NO sweets now and cut out potatos and most bread. I’m learning to love proteins and veggies. And rice.
Though, knowing she'll ask for my daily number from the meter, it keeps me honest and doesn't allow me to 'game' the system. Without daily meter tests, the A1C can be misleading.
I've had excellent results with Atkins for weight loss in the past. Unfortunately, I fell off the wagon. Beer and baby back ribs. Iced green tea lattes at Starbucks. Not all the time, but just enough to have my weight creep up over time. I really need to resume Atkins. I was much healthier and leaner when I stuck to that approach.
The A1C is not as accurate as people think it is. For example, people with anemia have higher A1C levels, and what they need is more iron, not more dieting.
I have a bad feeling about this. Treating the numbers is NOT the same thing as treating the disease. So many people are taking drugs to lower their blood sugar numbers, when there are no long-term studies that show it results in meaningful (that is, other than just lower numbers) reductions in serious complications. (I am speaking of Type 2 diabetes here.)
The data from the major studies cited in defense of all the oral diabetic meds have been seriously misused and massaged to muster even a miniscule amount of benefit.
“If there is no benefit, why tolerate any risk?”
http://abcnews.go.com/Health/Story?id=3232247&page=1
Excellent hard science blog on health matters:
Junkfood Science
http://junkfoodscience.blogspot.com/
When cold weather arrives your veins sink into your meat.
Just use the back of your hand, maybe both if they want more than two vials of blood.
Having lived in San Diego and Pocatello, I'm definitely better suited to a cold climate. As long as I'm wearing a medium long sleeve shirt, I'm good down to around +34 without a jacket. I can tolerate riding my motorcycle around in +26F as long as the streets have no ice patches. The summer weather here is bone dry. I handle that just fine. Add a little humidity and I'm soaked to the skin with perspiration.
There are at least several OTC A1C products...Metrika, HomeCheck-A1c, Appraise...Some are “developed” at home, others require the sample to be sent in to the lab. At least one (Metrika) claims their process is essentially what’s used in a lab. A quick review of topical forums suggests some of these have more than the usual testing error.
Time to pack up the skis and snowshoes and move back home.
We're just contemplating packing them up for the warm season. Locally, we have an alpine facility with a good ski lift and lodge. The cross country folks enjoy 25 miles of groomed trails and it's only 10 miles away from downtown Pocatello. Craters of the Moon National Monument allows cross country skis and snow mobiles during the winter. It's a fine area to putter around on a motorcycle in the summer. There is plenty of parking at the designated exhibits. I enjoy climbing into Boy Scout cave in the summer. It's well over +100F on top of the lava, yet the cave has ice on the floor. Digital pictures really bring out the colors of the minerals in the cave walls.
I left San Diego in Dec 2000. Many people consider that a "resort" town. Frankly, I find southeast Idaho has the kind of "vacation" environment that suits my interests. Mountains, rivers, lakes and sand dunes. It's nice to live in the middle of that kind of environment.
BTW, where is "home"?
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