The final two tests are fasting blood glucose (FBG) and hemoglobin A1c (HbA1c). FBG is a measure of how much glucose (sugar) is in the blood. High levels of blood sugar after an overnight fast could mean that you have diabetes. Type 2 diabetes is the number one cause of kidney failure.

For people with diabetes, the HbA1c test is a measure of average glucose levels over the past 2 to 3 months. The test should be done every 3 to 6 months. HbA1c levels should be below 7% to avoid long-term problems of diabetes.