Blood has several components, one of which is called hemoglobin. Hemoglobin is responsible for giving blood its red color and carrying oxygen throughout the body. The majority of hemoglobin is composed of hemoglobin A (about 90%). Within the hemoglobin A, there are several components, one of which is called hemoglobin A1C. The hemoglobin A1C is the part of blood to which glucose is chemically bound, and measures of A1C levels are therefore very important in glucose-related diseases such as diabetes.
A1C has some unique properties which allow scientists and physicians to easily measure its levels. It has a unique electrical charge as well as a different size compared to other hemoglobin particles, and scientists use both the charge and the size of A1C to separate it out using a process called high pressure liquid chromatography. The advantage to measuring A1C is that the levels of glucose are fairly stable and not subject to fluctuations associated with eating. A1C testing can be done at any time and does not require the subject to fast.
Importance of A1C and Blood Sugar Levels Chart Monitoring
A1C levels are dependent upon glucose levels in the blood. As glucose levels rise, so do the levels of A1C. Unlike home glucose monitoring, the A1C levels give a good picture of the average glucose levels within the blood over the previous six to eight weeks. While home glucose tests give snapshots of glucose levels, they may be misleading because many people test their glucose levels at times when glucose tends to be lower, such as right before a meal or in the morning. This can lead to a false sense of security about how well blood sugar is being controlled. A1C testing, on the other hand, gives a more accurate picture of actual glucose levels over time. A1C levels are expressed as a percent, and patients can use an A1C Chart to convert the percentage to an estimated average glucose (eAG) which can then be compared to daily glucose readings.
Limits of A1C Testing
While A1C testing gives a good overall picture of how well glucose is being controlled when converted to eAG in an A1C Chart, it cannot help patients monitor daily glucose levels and appropriately adjust insulin to deal with hyperglycemia or hypoglycemia. Daily glucose testing is essential to this process. Anyone with blood glucose level concerns must be aware of daily glucose numbers as well as A1C levels and compare the two using blood sugar levels charts in order to have an accurate picture of how well blood glucose is being controlled.
Some medical conditions can falsely inflate A1C levels, including excess alcohol consumption, kidney failure, and high triglyceride levels. Conversely, A1C levels may read falsely low in cases of blood loss or sickle cell disease.
People with diabetes need to have their A1C levels tested at least twice a year or as recommended by a medical professional. The American Diabetes Association recommends maintaining an A1C level of 7% or less, which corresponds to an eAG of 170 on blood sugar levels chart.