Diabetes blood Test - Glycosylated haemoglobin test
This test is not important to detect diabetes. It is more important to judge the control of diabetes during a period of 6-10 weeks prior to the test, in a person undergoing treatment for the disease.
The haemoglobin present in the red blood corpuscles has a tendency to get bound to glucose. The greater the blood-glucose concentration, the greater is the amount of glucose-bound (called glycosylated) haemoglobin. Such glucose haemoglobin linkage is quite stable and lasts for 60 to 120 days (the life-span of red blood corpuscles). Thus the amount of glycosylated haemoglobin is a sure guide to the concentration of glucose in the blood during the past 6-10 weeks (i.e., the degree of control over the disease achieved).
To detect the amount of glycosylated haemoglobin, the blood is passed through a chromatographic column, where glucose-bound haemoglobin separates out from normal haemoglobin. Normal and abnormal values of glycosylated haemoglobin have been given below.
|Amount of Glycosylated Haemoglobin
Control of Diabetes
|6 to 8 %
|8 to 10%
|10 to 12%
This test is most important for pregnant diabetic women because uncontrolled diabetes may risk the lives of the mother and the child; therefore ignorance about the degree of control of the disease is undesirable.