Objective: To establish reference values of glycemic parameters for continuous glucose monitoring in Chinese.
Methods: Forty-eight individuals with normal glucose regulation were observed with continuous glucose monitoring system (CGMS) for 3 days. Indexes in CGMS were analyzed, including mean level of 24 h blood glucose (BG) values (24 h MBG) and its standard deviation (SDBG), percentage of time above 7.8 mmol/L or below 3.9 mmol/L, area under the curve (AUC) of BG above 5.6 mmol/L, the largest amplitude of glycemic excursions (LAGE), mean amplitude of glycemic excursions (MAGE) and absolute means of daily differences (MODD).
Results: (1) The upper limits of indexes for continuous glucose monitoring were as follows: 6.5 mmol/L for 24 h MBG, 6.0 mmol/L, 6.3 mmol/L and 6.0 mmol/L for mean BG levels 1 h before breakfast, lunch and dinner respectively, 7.0 mmol/L, 6.7 mmol/L and 7.0 mmol/L for mean BG levels 3 h after breakfast, lunch and dinner respectively, 1.4 mmol/L for SDBG, 5.7 mmol/L for LAGE, 3.4 mmol/L for MAGE and 1.4 mmol/L for MODD. The percentage of time over 7.8 mmol/L was less than 9%, while the percentage of time below 3.9 mmol/L was less than 20%. The AUC of BG above 5.6 mmol/L was less than 0.9 d x mmol x L(-1). There was no statistical difference among sex subgroups (P > 0.05). (2) The correlations of 24h MBG with MAGE, MODD and SDBG were not significant (P > 0.05). MAGE was positively correlated with SDBG (r = 0.93, P < 0.01).
Conclusion: The reference values of glycemic parameters for continuous glucose monitoring are initially established and can be used as a temporary reference for clinical practice in Chinese. The CGMS profile can reflect the overall BG control and the feature of glycemic excursions in detail.