Maybe you have a family member with diabetes? Or you have been sent to the lab to check your FBG or even your A1C. Unfortunately, not only do you not understand the acronyms, you have no idea why you need these blood sugar tests. Here are some simple answers to these questions.
What is FBG and how do I prepare for the test?
If a doctor suggests that you should do a “FBG” test, this stands for Fasting Blood Glucose. To prepare for this test of blood sugar, you should
- Refrain from eating for 8-12 hours (listen to your doctor’s recommendation) before the test
- Try to schedule the appointment for first thing in the morning when fasting is not quite as difficult.
- Understand that anything you consume, even a small sip of juice, can alter the results.
- Ask your doctor if you should take your normal medications before or after the test. If you take the medications before the test, you should take them only with water
If you forget any of these tips and are not fasting, you should re-schedule your FBG test as the results will be inaccurate.
What do my blood sugar results mean?
When you get the results from this test you can expect the following types of numbers:
70-100 mg/dL* = NORMAL
100-125 mg/dL* = impaired fasting blood glucose or prediabetes
126+ mg/dL* = diabetes
Additionally, your doctor might ask you to do a random blood glucose blood draw. This can be done at any time of the day and the effect of eating on your blood glucose is what is being tested. If you take this assessment, the results would look like this:
Less than 125 mg/dL* = normal
More than 200 mg/dL* = diabetes
*mg/dL means milligrams per deciliter. That means you have that many milligrams (a very small unit of measure) of sugar per deciliter of blood (about 3.4 oz).
What is the HgbA1c test?
Recently, a newer test has become very useful in diagnosing and helping to monitor diabetes. Your fasting blood glucose measures the glucose at on one single point in time (think of it as a biopsy of the blood). If your FBG scores were outside the normal range, the doctor might suggest that you do a Hemoglobin A1c (HgbA1c) test, often just called A1C. This test checks the average amount of sugar in your blood over the past 2-3 months. It is a better indicator of your longer-term blood levels of glucose and thus the risk of diabetes and how well you are managing it if you already have it. The results you get on this test will look like this:
4.5-6.0% = normal
5.7-6.4% = could be a predictor of prediabetes and your doctor might advise exercise and dietary changes
6.5% or higher on two occasions = diabetes
8% or higher = uncontrolled diabetes
This number indicates the percentage of sugar absorbed within your hemoglobin molecules (the oxygen carrying component of blood). The higher the blood sugar has been over time the higher the percentage. Since red blood cells containing hemoglobin are produced all the time but each cell lasts about 120 days, this test estimates the average amount of glucose in your blood for recent weeks.
Now that I know my blood sugar numbers, what do they mean?
Now that we understand all the numbers, why do we care about them? Diabetes is a controllable but progressive disease. By understanding it and its progression, we can help to avoid complications which include:
- Damaged blood vessels (could lead to stroke or heart attack)
- Kidney damage
- Eye problems
- Circulation problems
- Memory problems
- Certain cancers
Dealing with a diagnosis of prediabetes or diabetes
A diagnosis of type 2 diabetes or prediabetes does not mean the end of the eating world as you know it. It might, however, mean that making changes in your diet and daily activity routines are required to manage the disease. Looking at the lab results with an educated eye and discussing them with your doctor will allow you to better understand your condition and make good choices in dealing with it. Obviously, preventing an elevated fasting blood glucose, before it develops in to full-blown disease, is extremely important.