Determination of Postprandial Glycemic Responses by Continuous Glucose Monitoring in a Real-World Setting.

Background: Self-monitoring of blood glucose using capillary glucose testing (C) has a number of shortcomings compared to continuous glucose monitoring (CGM). We aimed to compare these two methods and used blood glucose measurements in venous blood (IV) as a reference. Postprandial blood glucose levels were measured after 50 g oral glucose load and after the consumption of a portion of different foods containing 50 g of carbohydrates. We also evaluated the associations between postprandial glucose responses and the clinical characteristics of the participants at the beginning of the study.

Methods: 12 healthy volunteers (age: 36 ± 17 years, BMI: 24.9 ± 3.5 kg/m²) ate white bread (WB) and whole grain (WG) bread and drank a 50 g glucose drink as reference. Postprandial glucose responses were evaluated by CGM, IV and C blood glucose measurements. Incremental area under the curve (AUC) of postprandial blood glucose was calculated for 1 h (AUC ) and 2 h (AUC ).

Results: After the consumption of white bread and whole grain bread, the AUC did not differ between CGM and IV or C. AUC of CGM showed no difference compared to C. Correlation analyses revealed a positive association of age with glucose AUC ( = 0.768; = 0.004) and WG AUC ( = 0.758; = 0.004); fasting blood glucose correlated with WG AUC ( = 0.838; < 0.001).

Conclusion: Despite considerable inter-individual variability of postprandial glycemic responses, CGM evaluated postprandial glycemic excursions which had comparable results compared to standard blood glucose measurements under real-life conditions. Associations of AUC and AUC postprandial glucose response with age or fasting blood glucose could be shown.