Blood tests are fairly routine lab work for individuals with type 1, type 2, gestational diabetes, and juvenile diabetes. You may have to get lab work more than someone without diabetes. If you don’t have diabetes mellitus, you may have labs done yearly with your routine physical. However, if you are diabetic, you may have to have lab work done every 3 to 4 months. Many people have the blood tests done, while having no idea what their lab values mean. The rest of this article will be composed of tips to help you understand what your blood tests mean to your overall health.
- Fasting Blood Sugar: One of the lab tests that is important to you, as a diabetic, is the fasting blood sugar (FBS), also known as fasting glucose level. It is important that you have nothing by mouth for several hours before the FBS. You are usually instructed to be NPO after midnight, which means to take nothing by mouth from that time until the test is drawn. The normal level of a FBS is 60 to 99 mg/dl. If your fasting glucose level is 100 to 125 you have an impaired fasting glucose. A diagnosis of diabetes mellitus is made when the individual has a fasting glucose of 126 or higher. If your FBS falls into the range of 100 to 125, your doctor may order a glucose tolerance test (GTT).
- Glucose Tolerance Test: A glucose tolerance test determines diabetes blood glucose levels, and can be performed orally and intravenously. However, the intravenous glucose tolerance test is not widely used, and will not be discussed here for that reason. The oral glucose tolerance test (OGTT) is done while you are fasting. You will be instructed to not eat or drink from midnight to the time of the test. You will be given a certain amount of glucose solution. The lab techs will draw your blood prior to the test to have a base line, and then your will have blood drawn every 30 to 60 minutes for a period of 3 hours. The normal oral glucose tolerance test values are 95 mg/dl for fasting (before the test), below 180 at the 1 hour blood draw, below 155 at the 2 hour blood draw, and below 140 at the final blood draw. Any values higher than the minimums will indicate a diagnosis of diabetes.
- Blood Urea Nitrogen (BUN): Diabetics are often at risk for kidney failure. Failure of the kidneys is characterized by the kidneys not filtering properly. A blood urea nitrogen test measures kidney function. The BUN rises in correlation to the severity of kidney damage. Normal BUN lab values are 7 to 14 mg/dl. The BUN measures the waste products in your blood that are not being filtered by your kidneys. Thus, BUN tests with values 50 mg/dl or higher are indicative of renal failure.
- A1C Test: The A1C test is diabetic testing to evaluate how your diabetes treatment is going. You can check your blood glucose levels each day, multiple times a day, but your doctor may want to see how you are doing over time. The A1C test is a test that measures your glycated hemoglobin, which measures the amount of blood glucose stick to the proteins in the hemoglobin as the red blood cells have been exposed to in their 120 day lifespan. The more glucose molecules stick to the proteins, the higher the glucose level in the blood plasma. To know what your A1C test level is, you will need to contact your doctor. If the result of your A1C test is below 7 percent you are managing your diabetes well. Thus an A1C level 8 percent or above indicates your diabetes is not well controlled.
Knowing your lab values will help you better understand the state of health you are in. The more you educate yourself on routine labs and diagnostic testing the better you will understand how healthy you are. Don’t be afraid to talk to your doctor about any questions you have about any of the blood tests that you have to undergo.