I am 48 years old, and I was told I have prediabetes. I consulted a few doctors, and one of them told me that glucose meters are not accurate because they use capillary blood and that venous blood is more accurate? How true is this?

Capillary blood and venous blood can differ as much as 10-15%. Using a glucose meter properly will be accurate and effective. Additionally, if your physician obtains your blood in the office and sends it to a lab, the time it sits in the office awaiting pick-up could affect the results.

You could try getting a glucose at a local lab or hospital and using your glucose meter at the same time. If the results are within 5%, you can be assured that the meter is quite accurate. One other thing to mention, the place where you obtain your blood for the glucose meter may determine the extent of the difference — that is, arm vs. finger. Alternate sites, as they are called, can differ from the fingers by a similar percentage.

ABS

[Editor’s comment: totally agree with Dr Schorr’s comments.However, blood glucose values obtained with a meter should not be used for diagnostic purposes. See Classification and Diagnosis of Diabetes Guidelines for discussion of criteria for prediabetes (previously called impaired glucose tolerance).

SS]