Objective: To decipher the characteristics of real-life glucose profiles in normal glucose tolerance (NGT) persons by continuous glucose monitoring system (CGMS).
Methods: Forty NGT subjects confirmed by oral glucose tolerance test (OGTT) completed a 3-day period of glucose monitoring via CGMS.
Results: The values of 24 h mean blood glucose (MBG), standard deviation of MBG (SDBG), mean amplitude of glycemic excursions (MAGE), largest amplitude of glycemic excursions (LAGE) and means of daily differences (MODD) were 6.0 ± 0.7, 0.9 ± 0.1, 1.9 ± 0.8, 2.9 ± 1.4 and 1.1 ± 0.1 mmol/L respectively. Two of them experienced asymptomatic hypoglycemia defined as glucose concentration < 2.8 mmol/L. And 72.5% (29/40) subjects reached glucose concentrations > 7.8 mmol/L for 5.2 ± 4.6 hours. In addition to higher glucose concentration (FPG: 5.0 ± 0.4 vs 4.8 ± 0.3 mmol/L, MBG: 6.4 ± 0.7 vs 5.7 ± 0.5 mmol/L), the subjects with glucose concentrations > 7.8 mmol/L showed more dramatic glucose excursion represented by higher SDBG (1.1 ± 0.3 vs 0.6 ± 0.2 mmol/L), MAGE (2.3 ± 1.1 vs 1.1 ± 0.3 mmol/L), LAGE (3.3 ± 1.2 vs 2.0 ± 1.0 mmol/L) and MODD (1.2 ± 0.4 vs 0.9 ± 0.3 mmol/L) versus those with glucose concentrations within 7.8 mmol/L.
Conclusion: CGMS provides more detailed information of real-life glucose profiles in NGT subjects. And 72.5% NGT subjects in the present study spent a considerable amount of time at pre-diabetic or even diabetic glucose levels characterized by more predominant glucose excursion.