Originally Posted by Vividangel1984
Lets say if you are obese and might have diabetes and never get it checked to see if you have it. If you lose weight, and then go to the doctor and get a simple blood test. Will it give a false negative on the diagnoses since your blood sugar is controlled with the weight loss, but you really do have it?
There are 3 tests that are used
The fasting glucose test is often the only test they do. Unless specifically looking for diabetes. If over 126, the chances of having diabetes is very high and they will probably proceed with the other tests. The problem with this test is even if under 100, it does not mean you don't have diabetes.
The 1ac test is an average over a 3 month period. This ones tells how your blood sugar behaves over a long period of time. If this is high and your fasting is low you may have diabetes. If this is low and your fasting is low, chances are low you have diabetes.
The OGTT is a test that takes 2 hours. They make you drink a sugary solution and test your sugar levels before and after. This is probably the most conclusive test but the one they do less often.
I know my doc does the fasting, the 1ac and based on the results, asks for an OGTT.
So if they only do the fasting test, you could easily pass and yet still be diabetic. Several people here have very good fasting levels, yet are diabetic. They would probably fail the OGTT and may have higher than normal 1ac results.