Self-Testing and Hemoglobin A1c (HbA1c) Backgrounder


Self- Blood Glucose Testing: When people with diabetes test and control their blood sugar, they can reduce their risk of eye, nerve and kidney damage by as much as 60 percent. People with diabetes can use the information from daily blood sugar testing to help them and their healthcare professionals make decisions about food, exercise and medication that will help keep their overall blood sugar in a healthy range.

There are two different kinds of recommended tests that measure blood sugar: The first is day-to-day blood glucose testing performed by patients using a blood glucose monitor on a fingertip or perhaps an alternate site, such as the forearm. This self-monitoring of blood glucose gives patients information they can use to make decisions about factors that affect their blood glucose levels. The other test, called the hemoglobin A1c test, is ordered by a doctor and performed in a lab. The American Diabetes Association (ADA) recommends getting an A1c test at least twice a year.

What is a Hemoglobin A1c test and what does it do? The hemoglobin A1c test is a blood test ordered by a doctor and performed in a lab. A1c test results show the average amount of sugar (glucose) that has been in a person's blood over the last two to three months. The results give healthcare professionals the information they need to make appropriate adjustments to their patient's treatment plan to prevent complications. An A1c test is a measure of a patient's diabetes control over time and is not a substitute for daily blood glucose testing.

What does the A1c test measure? Sugar in the bloodstream can become attached to the hemoglobin (the part of the cell that carries oxygen) in red blood cells. The higher the blood sugar level, the more sugar attaches to red blood cells. The hemoglobin A1c test measures the amount of sugar sticking to the hemoglobin in the red blood cells. Results are given in percentages. A score of less than 6 percent is typical among people who don't have diabetes, according to the American Association of Clinical Endocrinologists (AACE). AACE also states that the higher the value above normal, the greater the risk for diabetes-related complications including blindness, kidney disease and nerve damage. In fact, levels above 9 percent show poor control and levels above 12 percent show very poor control.

Why is the A1c test important? Controlling A1C levels can benefit everyone with diabetes. A major diabetes study, the Diabetes Control and Complications Trial (DCCT) showed that lowering one's hemoglobin A1c level can delay or prevent the development of serious eye, kidney, and nerve disease in people with diabetes. The results of another major study, the United Kingdom Prospective Diabetes Study (UKPDS), showed that for every 1 percentage point reduction in A1c levels, there was a 35 percent reduction in the risk for developing microvascular complications (eye, kidney and nerve disease).

How often should the A1c test be done? The ADA recommends that people with diabetes have a hemoglobin A1c test at least twice a year. The ADA also suggests that people whose diabetes is out of control (2/3 of all people with type 2 diabetes in the U.S. are out of control) should get the test more often if their blood sugar level stays too high or if their healthcare professional makes any change in their treatment plan.

What is the A1c testing goal? The ADA recommends that people with diabetes keep their A1c levels below 7 percent, but not everyone can meet that goal. A change in treatment plan is almost always needed if test results are over 8 percent. The ADA recommends a score of less than 7 percent and AACE recommends a score of 6.5 percent or lower. Levels can range from normal to as high as 25 percent if diabetes is badly out of control for a long time.

The relationship between daily testing and A1c levels: Testing one's blood sugar daily can help people with diabetes manage their blood glucose levels on a day-to-day basis. Day-to-day blood glucose testing is like daily homework: your homework score tells you how you are doing right now and helps you make adjustments. An A1c test is like a quarterly or semi-annual report card: your A1c score provides an overall progress report of your blood glucose control. The results of an A1c test show a person's average blood sugar level over the past two to three months. These results can help patients and their doctors see how well their treatment plan is working over time.

  • How Often Should I Test? The American Academy of Family Physicians (AAFP) guidelines on testing note that the frequency with which you test your blood sugar level varies according to several factors, such as whether you take insulin or diabetes pills, and your diet and level of exercise, as well as your A1c levels. Consult with your healthcare professional to find out how often you should test and before making any changes. Also, talk to your healthcare professional about any questions that you may have.
  • The AAFP guidelines recommend that people with diabetes who take insulin (with or without diabetes pills) test at least three times per day. Those taking diabetes pills only, but whose A1c levels (i.e., average blood sugar levels over the past two to three months) are higher than the recommended range should test two to four times daily. Those who are controlling their blood glucose levels with diet and exercise only, or taking diabetes pills only and whose A1c levels are in range, will need to test less often and should check with their healthcare professional.
  • AAFP guidelines also state that you should test more often when your diabetes medicine or dosage changes, your diet or activity levels change, and when you are sick. Consult with your healthcare professional before making any changes or for any questions that you may have.

A Word of Encouragement: Diabetes is not a death sentence. If you think you have symptoms, don't ignore them. Establishing a plan for managing your diabetes and treating your condition is the quickest way to control your blood sugar levels and start feeling better. You can live a full and active life as long you keep your blood sugar levels - including your A1c levels - in a safe and healthy range, as determined by your healthcare professional.

About LifeScan LifeScan,Inc., a Johnson & Johnson company and the maker of OneTouch® Brand Blood Glucose Monitoring Systems, is committed to creating a world without limits for people with diabetes by providing fast, accurate and easy-to-use products. LifeScan participates in health fairs and works closely with diabetes health educators and community-based organizations, as well as the media, to educate the Hispanic community about the importance of effective diabetes management. LifeScan has bilingual operators available at 800 381-7226 to answer questions and a bilingual consumer Web site at