I’m a 37-year old normal weight woman. On my last blood tests, my A1c was 6.1 and my fasting glucose was 118 mg/dl [6.6 mmol/L] so my endocrinologist showed me how to test my blood sugar and said he would decide whether I needed an OGTT based on the results.

I’m finding that if I eat a significant source of carbohydrates, i.e., bread, or any type of grain or pasta, my blood sugar stays between about 180 mg/dl [10.0 mmol/L] to 240 mg/dl [13.3 mmol/L] for two to three hours. If my carbohydrates come from vegetables and dairy, then it’s in the 125 mg/dl [6.9 mmol/L] to 150 mg/dl [8.3 mmol/L] range after eating. So, it would seem that cutting grains out of my diet would be the way to address the problem. Do you think I would learn anything else from doing the OGTT? Do you see anything wrong with cutting out carbohydrates this way?

I also have Grave’s disease. Could that be causing the blood sugar problems?

At present, your single fasting glucose puts you in the range of impaired fasting glucose. You do not meet the criteria for type 2 diabetes. However, sampling was only on a single day. With day-to-day variability, this may be higher or lower. What the OGTT does is allow the diagnosis to made with a single test. The test is performed with a fasting glucose, followed by an oral glucose load of 75 grams after not eating anything since the night before, and a follow-up two hour post-load glucose. If the glucose at two hours is greater than 200 mg/dl [11.1 mmol/L], you have diabetes. If the value is between 140 mg/dl [7.8 mmol/L] to 200 mg/dl [11.1 mmol/L], you have impaired glucose tolerance with a high risk to advance to type 2 diabetes.

It is unlikely that removing grains from your diet is the answer. The more important issue is an appropriate amount of grains. If a very little grain-associated carbohydrate intake causes your blood sugars to shoot up, you might truly have diabetes and would be better off being treated. Home glucose monitoring tests results do not fulfill the diagnostic criteria for diabetes, but they will help your doctor see the fasting and meal-associated glucose results and provide more information as to whether it is likely to pursue the other tests, such as OGTT or additional fasting glucose measurements. The hemoglobin A1c is not sensitive enough to diagnose diabetes.

JTL