The test is also known as glycosylated haemoglobin test. Haemoglobin is found in red blood cells. When glucose is present in the blood, it attaches to the haemoglobin making it glycosylated haemoglobin or HbA1c (Fig 1. a).
Fig 1. a) Haemoglobin in the blood (red, rectangle) attaches with glucose in the blood (green, circle) to form glycosylated haemoglobin.
In case blood glucose level is well within control and gives stable results, the test is performed every six months intervals. The long-term or chronic complications of diabetes are those that characteristically occur after years of high blood sugar levels. These are diabetic macrovascular and microvascular diseases. The long term complications correlate well with A1c levels.(Web ref 2).
Wild and Bains (2004) cautioned clinical laboratories and point-of-care testing to be careful of the interferences produced in assays by variant Hbs. The majority arise from point mutations in the , , , or Hb chains. Herman et al (2007) also raised the important question of whether A1c can be used as a diagnostic test for diabetes detection and control in ethnic minorities whose mean A1c concentration vary significantly from whites. In the light of these observations the current project intends to analyse literature particularly on blood glucose tests, long term complications of high blood sugar and applicability of HbA1c test to ethnic diabetics.
Studies have shown that glycohaemoglobin values in the "better ranges" correlate with less incidences of diabetic complications later in life (Table 1; Fig 1 b). ...