I was diagnosed with type�2 diabetes based on one random blood test which showed a fasting blood glucose of over 200 mg/dl [11.1 mmol/L], and since that time, I have monitored my own blood glucose. Generally, I have tested about three times a day for four to five weeks now, and my monitor tells me that my four week average is 102 mg/dl [5.7 mmol/L], and the highest reading I have had was 181 mg/dl [10.6 mmol/L]. Generally, the levels are around 100 mg/dl [5.7 mmol/L].

I’m over 50, slightly overweight, I have diabetes in the family, and I exercise frequently. I guess I just don’t understand how to interpret my own testing results. Does this sound like I have diabetes for sure or are these good readings? Should I get some kind of other test to make sure? Does someone without diabetes ever have readings over 126 mg/dl [7 mmol/L]?

There are Classification and Diagnosis guidelines that have been adopted by the American Diabetes Association for making the diagnosis of diabetes. That means you either meet the criteria or don’t meet the criteria. Any suggestion of borderline diabetes should be stricken from the medical vocabulary. The recommendations have put an emphasis on the use of the fasting blood sugar. That means nothing to eat for eight or more hours, tested in the morning before breakfast. The test should be performed in a lab, such as one used by your physician.

Home blood sugar monitoring is not used to make the diagnosis. It is used for monitoring the interventions used. A fasting blood sugar value greater than 126 mg/dl [7 mmol/L] on two separate occasions is the criterion most often cited. However, the use of the 75g oral glucose tolerance test is also appropriate.

If you want one test to make or dismiss the diagnosis, I would recommend the oral glucose tolerance test. It may also help to identify impaired glucose tolerance or prediabetes. This condition is not diabetes but carries a risk of diabetes within 10 years. It also carries a high risk of cardiovascular disease. Some have suggested that the hemoglobin A1c, may have some benefit. However, it is not sensitive at the border between high normal and frankly elevated.

In response to your second question, yes, people without diabetes have blood sugars over 126 mg/dl [7 mmol/L]. These usually occur after meals. The difference is that people with diabetes have a higher peak after meals and have a longer duration at the high sugar after the meal.

JTL