Meal Glucose Tolerance Test (MGTT): A Validation Study

Continuous Glucose Monitoring devices (CGMs) allow for a dynamic assessment of postprandial glycemic variability (GV). Using a CGM device, such as the Freestyle Libre Pro, researchers can monitor research participants blood glucose levels continuously for up to 14 days in a free-living environment. Because of this, researchers have begun to rely on CGMs as a tool to understand chronic changes in glycemic responses. PURPOSE: For this research study, we are investigating the viability of using a CGM and standard meal test (MGTT) to assess the glycemic response against a standard Oral Glucose Tolerance Test (OGTT). METHODS: On two separate days after fasting for 10 hours, each participant was randomized to receive either a standard meal test (MGTT) or 75g glucose beverage (OGTT). During the 2hr postprandial period, simultaneous glucose measurements were taken via CGM and blood measurements every 15 minutes (9 measurements each). The area under the curve (AUC), peak glucose (PG), and time to peak (PG) for each treatment and testing method will be analyzed. RESULTS: A Preliminary assessment showed that the mean values between CGM and blood measurements were significantly different for both standard test meal and drink conditions (p Another preliminary assessment showed that the mean values of the meal test and glucose drink were not different between CGM (p=0.83) and blood (p=0.18) testing measurements. CONCLUSION: This research is ongoing, and the results presented are preliminary. However, the data does suggest that using a CGM in conjunction with a MGTT may be a reliable method for evaluating standardized glycemic response in a free-living conditions.