Objective: To probe more details about the daily glycemic excursions in normal glucose tolerance (NGT) individuals.
Methods: The fluctuations of glucose levels in 43 NGT individuals were measured by continuous glucose monitoring system (CGMS) for (72 +/- 7) hours.
Results: The number of glucose values detected by CGMS amounted to 858 +/- 77 with a mean absolute difference (MAD) of 8.9% +/- 3.0%. The CGMS values in this study were significantly correlated with the plasma glucose and capillary glucose measurements (n = 204, r = 0.93; n = 804, r = 0.95; both P < 0.001). The glycemic excursions revealed that the daily glycemic levels were lower at night and before meals, the climax of daily glycemic level tended to appear 1- 2 hours after meals, particularly after dinner. The average glycemic value was 5.3 mmol/L. The daily glycemic peak and nadir levels were (7.8 +/- 1.4) mmol/L and (3.9 +/- 0.7) mmol/L respectively; the difference between maximal and minimal glucose levels was (3.9 +/- 1.6) mmol/L. Twenty-seven of the 43 individuals (63%) showed glycemic excursion above 7.8 mmol/L, and 9 individuals (21%) showed brief glycemic excursion below 2.8 mmol/L. During 95% (74% - 100%) of the daytime the glycemic level drifted to and fro between 3.3 mmol/L and 7.0 mmol/L; and during 99% (87% - 100%) of the daytime the glycemic level drifted to and fro between 2.8 mmol/L and 7.8 mmol/L.
Conclusion: The profile of glycemic excursion in NGT individuals may have an important significance in defining the diagnostic cut-points and targets for glycemic control on diabetes mellitus.