Importance of A1C and Blood Glucose Readings

Which is more important: The A1C or blood glucose readings? In asking several type 2 friends, only one said you need both for good diabetes management. So, we will look at the two tests and their differences.

The A1C test: The A1C test measures the amount of glucose on your red blood cells and gives an average of your blood glucose control over a period of four months. This test is generally ordered by your healthcare provider every 3 to 6 months, depending on your blood glucose control and the type of diabetes you have.

The goal standard set by the American Diabetes Association is for you to keep your A1c percentage at 7.0 or below. The American Association of Clinical Endocrinologists prefers the percentage to be 6.5 or below. The American Geriatrics Society recommends A1c levels of 7 percent or lower for healthy adults and less stringent levels for less healthy adults of 8 percent or lower.

Many individuals with type 1 diabetes prefer readings above 5.5 and below 6.5 percent for the A1C. Individuals with type 2 diabetes prefer A1C readings below 6.5 percent to a low of 4.5 percent.

Blood glucose metering: Checking your blood glucose with your personal meter gives you immediate information and helps you make decisions for your diabetes management. Metering helps you determine how to dose your insulin, handle exercise and illness, and tell you if you're on track with your diabetes care.

Even if you're not on insulin, blood glucose metering even several times a week tells you how well you're doing, if you need to make lifestyle changes, or if you need to contact your healthcare provider for help.

The two tests together inform your provider of the long range control over the past 3 to 5 months and the meter reading tells the day to day control. I sometimes use the analogy; the A1c is the motion picture and the blood glucose meter readings are the camera snap shot picture.

What if the A1c and blood glucose meter readings don't match?

• Measurement errors could result from the meter being off, an incorrect lab test, anemia, recent blood transfusion, nutrition deficiencies, iron or certain medications. This is rare.
• If there is good A1c range but the blood glucose readings show wide swings from high to low, the doctor needs to assess treatment and management issues.
• It's important to make sure there are enough readings to give a fair representation.
• Blood glucose needs to be tested at the right times, post meal.

Meanwhile, Reuters Health recently reported that frequent blood sugar testing was strongly associated with better diabetes control in a large new study that concludes public and private insurers should not be limiting test strip supplies.

This last paragraph helps explain the problems for many type 2 diabetes patients on oral diabetes drugs and not on insulin. Some insurance companies even restrict the number of test strips for type 1 and type 2 patients on insulin.