Real-Time CGM Can Help Shape Patient Education, Glycemic Index Measures in T2D

Data from real-time continuous glucose monitoring (rtCGM) has been proved a reliable measure for the glycemic index (GI) of a variety of rice-based meals in a new study from Malaysia, indicating the diabetes technology may have larger-scale utility as a GI measuring tool and for patient education among those who may be classified as overweight or obese.

The authors of this new study cited the convenience and sophistication of rtCGM systems in coming to this conclusion, as well as that the data these systems produce are more robust, and they published their findings in a recent issue of Foods.

The 14 study participants were young adults with a mean (SD) age of 22.8 (4.6) years, and their mean body mass index (BMI) was 32.9 (5.8) kg/m². To be included in this study, they had to have a BMI of at least 25 kg/m² and a fasting blood glucose measure of less than 5.6 mmol/L. They were randomized to 1 of 3 rice-based meals, each with 50 g of carbohydrates: white rice meal (WRM), brown rice meal (BRM), or parboiled basmati rice meal (PBRM). A 50-g glucose reference drink was added on alternate days. In addition to the rice, 100 g each of grilled chicken and salad were served with the meals.

The primary outcome was the impact on postprandial hyperglycemia, which has been associated with a greater risk of type 2 diabetes (T2D) as measured by GI, glycemic variability, 24-hour mean glucose levels, and target glucose ranges.

“Rice variety preferences were compared with those of baseline data and determined at the end of the study period,” the authors wrote.

Of the 3 rice-based meals, the mean glycemic index was lowest for the PBRM and highest for the WRM:

• PBRM: 45.35 (2.06)
• BRM: 56.44 (2.34)
• WRM: 83.03 (2.19)

In addition, the reference drink had the highest mean glucose level and the PBRM the lowest:

• Glucose reference drink: 5.37 (0.54) mmol/L
• WRM: 5.29 (0.62) mmol/L
• BRM: 5.03 (0.45) mmol/L
• PRRM: 4.87 (0.66) mmol/L

GI is measured on a scale of 0 to 100, and foods that come in high on this scale are those that tend to be digested fast and cause blood sugar levels to escalate quickly. A 50-g measure of food, as was administered in this study, is the standardized amount given when determining a food’s GI.

For 24-hour glucose, PBRM was also significantly associated with a lower overall mean measure but a higher in-target percentage compared with the WRM (P < .05). In addition, there was a nonsignificant association seen with lower GV vs the WRM (P < .05).

Participants’ meal preferences were also shown to change over the course of the study. At the start of the study, the overwhelming preference was for the WRM, at 64.3%), but by the end this had shifted to the PBRM, at 71.4% (P < .05). Participants stated they changed their minds because of the data they saw come in from their rtCGM. Postprandial glucose levels were measured every 15 minutes by the participants’ rtCGM sensor—which was worn for at least 10 days—and the data were then explained to the participants.

The study authors noted that approximately 90% of individuals who have T2D are classified as overweight or obese and that close to 39% of the global adult population falls into those same weight categories. In addition, “Rice is the second highest consumed staple food in the world, supplying 16.5% of the global calorie intake and providing up to 66% of the daily energy intake in Southeast Asia, where the prevalence of obesity has recently increased,” they wrote.

These findings are noteworthy—particularly for those who consume white rice daily—because vs the widely used method of evaluating GI over a 2-hour period, using rtCGM data can help to inform the glucose profile over a 24-hour period. In addition, the authors wrote, glucose levels do “not drop back to baseline after a 2-hour period for all foods, highlighting the importance of evaluating these levels beyond the 2-hour period.” The meals they served also mimicked the type of meal consumed daily in the general population of Malaysia.

“This present study suggests that the rtCGM system can potentially be used as a new technique in measuring the GI of foods as it is convenient to use and is more sophisticated, as it produces more robust data continuously over 24 [hours] and is less invasive,” the authors concluded. “The rtCGM system can also potentially be used as an educating tool producing real-time information for overweight and obese individuals to select lower GI foods in their daily diet.”

Reference

Chekima K, Wong BTZ, Noor MI, Ooi YBH, Yan SW, Chekima B. Use of a continuous glucose monitor to determine the glycaemic index of rice-based mixed meals, their effect on a 24 h glucose profile and its influence on overweight and obese young adults' meal preferences. Foods. Published online March 28, 2022. doi:10.3390/foods11070983