Lg Cwd
Need Help

Submit your question to our team of health care professionals.

Current Question

See what's on the mind of the community right now.

Meet the Team

Learn more about our world-renowned team.

DTeam Archives

Review the entire archive according to the date it was posted.

April 30, 2001

Blood Tests and Insulin Injections

Question from Elgin, Illinois, USA:

Our 18 year old daughter has had type�1 diabetes since age five. She is very brittle, and her hemoglobin A1c averages between 11-13%. However, recently her monitor's memory indicates her four daily test readings are normal. We called the meter manufacturer to find out if she could be "faking" her monitor readings somehow, but were assured that she could not be doing that. However, in an answer you gave to another parent, you said "Some teenagers are very sophisticated at getting the meter to actually read lower than it should be either changing their technique or the meter code." Can you give me specifics on what you mean by "changing her technique or meter code?" We told her we'd help her finance a new car if she got her numbers under control, and I'm afraid she's found a way to dupe us into thinking she's done that, but her A1c indicates otherwise.


There are many ways to get false low readings. One is to take blood from a finger that is not dry. Another is to use too little blood (you have to get enough on the strip so the meter registers, but not enough to get an accurate reading). Your daughter’s meter comes with a code strip for each bottle of strips, and she could be using an old code strip, but it is unlikely that she could get such consistent readings. She may be testing with a control solution and not her own blood.

I usually recommend that parents watch their teens test their blood in situations like this. I also recommend that the teen do duplicate readings each time with two separate brands of meters (with memories). It is hard to falsify two different brands of meters in the same way (unless you are testing with control solution).

If you plan to document that she is falsifying readings, it is important to think out in advance how you will handle this information. I would not recommend you use a car as a reward for good blood sugars. I would recommend that you use honesty in testing and responsibility not driving without testing and avoiding lows while driving. Blood sugar results shouldn’t be her “report card”, but a guide to controlling her diabetes. You can start using these issues now just to let her drive. You don’t want her to get into an accident trying for good blood sugars and going low.

Additional comments from Dr. Donough O’Brien:

First of all the term ‘brittle’ does not imply a special form of diabetes, it is an euphemism for poor control which in your daughter’s case is confirmed by an A1c range that is well above that required for optimal control. The situation that you describe is one of some urgency and apart from getting help from the Medical Social Worker in her diabetes team to help disentangle the underlying problem she should have an eye exam and a quantitative urine microalbumin test to see if there is evidence of early treatable diabetes complications.

As to the blood sugar levels in the memory of her meter: I talked to one of our nurses who came up with three possibilities

Testing the control solution and not the blood which can apparently give quite a wide range of results if not done too carefully
Washing the hands before testing; but not drying them so that the blood sample is diluted and
Having a cooperative significant other who volunteers samples on the basis of a future loan of the car.

It really is important to sort this out so hold back for now on the Ferrari!


[Editor’s comment: Although this is a remote possibility, some hemoglobin variants and medications can be falsely elevate the hemoglobin A1c value. To rule these out, you might ask your daughter’s physician to test for these things or to have her A1c checked by a different methods which is not affected by this phenomenon.