My 13 year old son was diagnosed with type�1 diabetes four months ago. At the time of diagnosis his HbA1c was 13% and one month later it was 8%. He and I have been working very hard to manage his blood glucose levels with diet, exercise and (of course) insulin, but his last HbA1c was 9%, and his pediatrician told him that he must have been “cheating”.

I realize that 9% is too high, but considering his age, couldn’t there be fluctuations in his levels that we just aren’t detecting? I feel that the doctor’s remark was insensitive, and he is risking alienating my son from proper control, especially after trying so hard to manage the huge lifestyle changes and adjustments that come with the diagnosis of this disease. This last week his readings have been higher, for which we are making adjustments in insulin dosages and diet. Do hormones cause a rise or fall in blood glucose at unexpected times? Will there always be these ups and downs? In the first four months can we really establish ideal diabetes management? Can there be any other explanation rather than “cheating”? We’re very discouraged at this point and need some outside advice.

I am sorry that you are feeling so discouraged, and I regret that your son’s pediatrician jumped to the “cheating conclusion.” Your questions are good ones and I hope that I answer them.

First of all, it may be helpful to know what the hemoglobin A1c is really measuring. It is measuring the percentage of glucose that is “stuck” to the blood protein called hemoglobin. We all have some glucose ‘stuck’ to hemoglobin, and depending on the technique used to measure it, the value is somewhere between 4 and 7%. It is very important: to realize that there are several different ways that this compound can be measured (and some variations of the HbA1c compound.) So, it always helpful to know the normal ranges for the lab that is measuring it. If your son’s HbA1c was measured by one technique at the last visit and a different technique more recently, then the comparison of the numbers may not be so helpful. Sometimes the blood sample may need to be measured at different places, say for instance, because of change in your insurance plan contract. Ask your doctor if the same lab is being used.

However, a lab test is only a test and may be corrupted for several reasons. One of my favorite “rules-of-thumb” is that “the most common cause of an abnormal laboratory test…is an abnormal laboratory.” Does the HbA1c correlate with the readings from the meter? If so, then the HbA1c may be true and you and your doctor and your son need to consider possibilities (including “cheating”). If the values don’t match very well, then the HbA1c test may have been erroneous for some reason.

Frankly however, 13 year olds with diabetes are known to go off their meal plan and are having other hormonal changes of puberty that can cause their glucose levels to go up and to make them more resistant to insulin. If someone is optimally following their meal plan and taking appropriate doses of insulin, and exercising reasonably and checking glucoses and making adjustments (boy, that’s a lot of stuff to do, isn’t it?), then, four months into the diagnosis, I would hope that they would still be in the honeymoon. After the honeymoon, the HbA1c can fluctuate, up or down — depending on the control, but should do so in a fairly obvious pattern relative to the daily glucose checks, which should be done at least four times daily.

DS