What is the best blood test for diabetic people?

Tonya Bolden
Alternative & Complementary Medicine
The A1C Hemoglobin test. It determines a diabetic’s overall blood sugar average. The popular analogy is that the A1C results are to a diabetic what a batting average for a season is to a baseball player. Experts differ on how many times a year a diabetic should have an A1C test. Some say at least twice a year; others say three or four times a year. Most experts maintain that for most diabetics, the target number should be under 6 percent. Armed with your A1C test results, your doctor will know if you need adjustments in your meds.
Half the Mother, Twice the Love: My Journey to Better Health with Diabetes

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Half the Mother, Twice the Love: My Journey to Better Health with Diabetes

As a talk-show host and inspirational speaker, Mother Love used to have to just grin and bear it -- all that extra weight and the poor health that went along with it. Today she can truly smile as she...
Dr. Jack Merendino, MD
Endocrinology Diabetes & Metabolism
The hemoglobin A1c test, of course, because it gives you information about your average blood sugar levels over time. But let’s dig just a bit deeper. Is the A1c always the best test? Are there some situations where other tests are as useful or even more useful? You can probably guess that the answer is yes, or I wouldn’t pose these questions. 

The most important first point is that information about “average” blood sugar levels doesn’t give you any information about the fluctuation in blood sugar readings throughout the day, and understanding this diurnal pattern can be extremely important in terms of adjusting insulin or other medication. Another important point is that the A1c test takes several weeks to change, and you often need information more quickly than this. A similar test called a fructosamine will give information about average blood sugar levels over a much shorter time period --around 3 weeks or so, instead of 3 months. This can be very important in pregnancy, for example, where you really can’t afford to wait months to know that things are improving. 

In addition, the A1c test doesn’t reflect a person’s average blood sugar accurately in certain kinds of anemias. In sickle-cell disease or sickle trait, in thalassemia (also known as “Mediterranean anemia” or in hemoglobin C disease, there are abnormal hemoglobin molecules that interact with blood sugar differently from normal hemoglobin and give false results. Most people with sickle cell trait have hemoglobin A1c levels that a full point or more higher than they would be if they didn’t carry the sickle gene. In hemolytic anemias, red blood cells don’t last nearly as long in the blood as usual. Since hemoglobin A1c accumulates over time in cells, if the cells don’t live long then much less A1c will accumulate. Therefore, people who have hemolytic anemias have lower A1c levels than expected. 

Another blood test measuring 1,5-anhydroglucitol (usually called by it’s trade name, GlycoMark) can tell you whether you are having high blood sugar spikes and indirectly tells whether glucose levels are relatively stable or volatile.  

Finally, it’s important to remember that things other than blood sugar control are critical for people with diabetes.  LDL or “bad” cholesterol levels have a stronger correlation to heart disease than does the A1c level, for example, and blood pressure readings are more closely tied to stroke, a major cause of death and disability in diabetes.  

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.