Glycosylated haemoglobin and steady-state mean blood glucose concentration in Type 1 (insulin-dependent) diabetes.

Since glucose control and glycosylated haemoglobin varies asyncroneously, we have studied the steady-state relationship between these two factors. In Type 1 (insulin-dependent) diabetic patients with a constant haemoglobin A1c during the preceding 2 years, 15 ambulatory blood glucose profiles during a 5-week period showed a constant glucose level and provided a precise estimate of the mean blood glucose concentration. In addition, we studied 15 non-diabetic subjects who provided three glucose profiles and had one haemoglobin A1c determination performed. A good correlation was found for a curvilinear relationship (haemoglobin A1c = 2.07 X mean blood glucose0.596, r = 0.98). This close relationship indicates that glycosylated haemoglobin is a valuable, but not very sensitive, index of glucose control.