The Hemoglobin A1C test, created in 1976, is used to measure long-term success at blood-sugar control for diabetics. The test detects the amount of glycated hemoglobin in the blood. Glycated hemoglobin forms when glucose binds to hemoglobin (blood cells).
The test results are typically returned either as a number or percentage, both representing essentially the same thing. For example, a non-diabetic would be expected to have an A1C of between 4.0 and 6.0 or expressed differently, between 4% and 6%. For diabetics, a desire A1C is less than 7.0, and diabetics may experience increased risk of complications if their number is greater than 8.0. Complications due to high blood-sugars levels include peripheral neuropathy, loss of limbs, kidney damage, loss of vision, and increased risk of heart attack, stroke, and death.
This test can also be used to assist in the diagnosis of new diabetics or pre-diabetic patients. An A1C of 6.5 or higher is generally considered sufficient for such a diagnosis. To administer the test, a small amount of blood is collected in a clinical setting and analyzed in a laboratory. The blood required is generally somewhat more than used for daily blood-sugar testing, but may be drawn or taken with a lancet prick. Home testing is available and may in the future these kits may be considered essential diabetic testing supplies. Results are not as rapidly available as with regular blood-sugar testing devices.
The HBA1C test, unlike daily blood-sugar monitoring, can provide long-term information about levels that can be useful in adjusting medication dosage, fitness routines, and diet for both Type I and Type II diabetics. The test should be administered every three months to present the clearest picture of success in controlling blood-sugar levels. More often will not likely provide additional information. Consistent testing and adjustments to treatment regimens can reduce the likelihood of complications and improve overall quality of life for a diabetic. However, even with regular A1C testing, diabetics must continue daily testing, especially those administering insulin.
Some circumstances and conditions can affect the accuracy of the HBA1C test, including taking high dosages of certain supplements, such as vitamins C and E. High cholesterol may also influence test results. Diabetics should inform their doctor of any medications they are taking, including supplements. Kidney and liver disease may also impact test results. HBA1C is generally not used to identify gestational diabetes due to the relatively quick onset of this type and other factors.