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.
FReepmail me if you want on or off the diabetes ping list.
Thanks for ping. I had an epidural and my A1C was higher. The Doc said that could last for 3 months. Now it is back down below 7. I don’t know if taking more meds would have prevented that. I’ll check that out next time.
My doctor has been using the A1C test to track my progress for 4 years now. Nothing new to me.
I work for an Ophthalmologist and he uses this as a guide for how his diabetic patients are doing in controlling the blood sugars. We see a lot of patients with background diabetic retinopathy - please take care of yourselves!!!
A1c can be well below 7.0 ALL THE TIME yet you can have massive and dramatic insulin (and blood sugar) swings every single day.
Or, vice versa.
The consequences for the individual can be very different yet these symptoms occur in clusters within ethnotypes.
Treatments must necessarily be very different.
I think that’s sensible news. I’m so tired of the guilt and fright when my daily punctures are above 140, for example, but my A1C is 7 or below. I’ve long thought that one size does not fit all when it comes to determining who is seriously (or even actually)diabetic.
Suffered for years on metformin and other drugs, both alone and in combination, until I decided to treat myself. Now taking glyburide alone and doing pretty well. Last A1C was 7.3 (after a bout with shingles and an infection), and the one before was 6.5.
Illness and meds do make a big difference on your glucose levels, etc.
A cut point of 7 is insane. Yes, let’s wait until it’s right at the red line to treat the disease.
The cut point should be 5.5 for type two diabetes.
I also hope they’re still running the fasting. A new-onset type one child or LADA patient can have an only slightly elevated A1C if it’s caught soon enough. These people can die quickly without treatment.
The cut point should be 5.5 for type two diabetes
Agree ! BTTT!!!
Gee, I always considered the A1C to be the best test. So does my doctor. As many of you know, the A1C test is the best long term progress test and daily BS measurements get us through the day to day control.
I’m new to Metformin. What are some of the problems you had while on it?
ping
Anybody who’s diabetic should really be taking Benfotiamine.
It’s an anti-glycation agent, and it helps prevent retinopathy, neuropathy, etc.
Upset stomach and Lactic acidosis.
I was taking Jamumet which is a combination of Metormin and another drug to increase the amount of insulin.
When I first started taking it I started to develop symptoms of Lactic acidosis, so I stopped for a week and cut my dosage in half until I could tolerate it better
I believe Lactic acidosis is under reported and it can be a very dangerous condition if you aren't aware of the symptoms
Look it up if you are on any form of Metformin
If they’d used the HA1C test before I was actually diagnosed 20+ years ago they would have discovered I was diabetic. My blood sugar had been high for quite a while but my doctor assumed I wasn’t fasting when he drew the blood in the office for routine tests because I was complaining of feeling sick over a long period of time. They were in the area of 140-160 (acceptable blood sugar was higher back then. They didn’t have pre-diabetes as an official condition and if I remember what he told me was that over 190 was the absolute diagnoses of diabetes.). He thought I’d eaten less than 2 hours before since it was an hour or so after lunch (never asked). I hadn’t and in some cases I hadn’t eaten anything in 14 hours. He finally caught it when it was over 200 and spilling into my urine. When the subject of blood tests comes up I always suggest to people that they tell the doctor when they’ve eaten before they draw blood.
My new doctor at Kaiser views the HA1C as the gold standard and isn’t as concerned about the day to day readings that I take. He still believes in the day to day readings to help you stay on course but as a measure of how your doing he’s going to use the HA1C. The samples are snapshots and don’t measure what’s really going on over a longer period of time. For example the blood sugar could be staying high for longer periods of time and dropping near the time you test or it could be staying near the level you got when you test. His goal for his diabetic patients is to keep their HA1C reading below 7.0 and not have them try to push to keep it within the “normal” range. He feels that there are a number of complications that appear if you reduce the HA1C levels that low consistently.
I haven’t had any side effects that I know of, but it and the other medication I take are no longer working as well as they did so they’ve reduced the medications and added an insulin shot at night.
ping
About 3 months ago, I decided to inquire about new insurance coverage. That required a physical including a blood test. That test was much more comprehensive. The nurse was incapable of drawing blood from me. She went through 3 vacutainer needles and two butterfly needles before redirecting me to a local lab. The consequence was the 9 hour fast was extended to 12 hours. I ended up with a fasting blood glucose of 106 and A1C at 6.2. That was my first A1C ever. My dad was an insulin dependent diabetic. That was enough to point me into the local urgent care facility for a better physical. It's still a work in progress.
Thanks for the tip. Not evident from your comment is that you are talking about a common vitamin -- B1 - thiamine -- but there is some interesting research concerning this form.
This subject is of considerable interest to me. I’m 65 and a few years ago began to have some issues that suggested I might have problems. But the numbers didn’t reflect that.
But I was suspicious so what I have been doing is to do daily fasting glucose testing in the morning. (But do use a reliable meter) I have never had a diabetic reading after eating. Oddly enough it seems higher in the morning and from what I gather the readings can vary considerably over the day. What I do know is that weight gain around the middle (over 40” for men) is a danger sign and with advancing age should be watched carefully. What I do know is that I intend to keep a very close eye on this situation and will do whatever is required. The idea that I might go blind was enough to get my attention. Then come amputations, strokes and heart attacks. Diabetes is nothing to fool around with.
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