Continuous glucose monitoring: physiologic and pathophysiologic significance

Diabetes mellitus is a complex disorder of the energy metabolism. In the present paper, we have tried to illustrate the changes in the regulation of blood glucose levels encountered in the two main types of diabetes: Type 2 (T2DM) and Type 1 (T1DM) diabetes mellitus, compared with healthy, non-diabetic subjects. For this we used the MiniMed CGMS (Continuous Glucose Monitoring System) which allows the continuous in vivo blood glucose measurement over a 3-day period. The study group comprised 19 diabetic patients (14 T1DM and 5 T2DM cases) and 4 non-diabetic controls. The recording in normal subjects showed a glycemic variation between 46 and 118 mg/dl, suggesting the existence of a strong and efficient glycemic control mechanism. In T2DM patients, both on diet only or on oral antidiabetic treatment, the oscillation of blood glucose levels was significantly higher compared to that recorded in non-diabetic subjects. In T1DM patients with stable metabolic control blood glucose fluctuations were comparable with those recorded in long-term type 2 diabetic patients but the "mean" values of blood glucose over 72 hours were lower. The CGMS is a valuable tool in the detection of unrecognized hypoglycemic episodes and hyperglycemic postprandial peaks and allows the patient and the health care team to adjust the treatment regimen in order to improve glycemic control. From our point of view, the CGMS could offer valuable information for the knowledge of glycemic regulation in normal people and for the diabetogenic mechanisms in prediabetic IGT and IFG patients.