HBA1c :There should be an estimation of glycosylated haemoglobin at half yearly intervals. This test provides a long-term index of glucose control. This test provides a long-term index of glucose control. This test is based on the following rationale: glucose in the blood is complexed to a ceain fraction of haemoglobin to an extent propoional to the blood glucose concentration. The percentage of such glycosylated haemoglobin reflects the mean blood glucose levels during the red cell lifetime ( about the previous 2-3months ).Ref: Park; 23rd ed; Pg 396