69-LB: Postprandial 2-hr Rise in Insulin Is a Strong Predictor of Glycemic Responses to Different Meals in Healthy and Prediabetic Individuals: The PREDICT I Study

Objective: Postprandial glucose is a predictor of later diabetes and vascular complications. The study aims to identify determinants of inter-individual variability in postprandial responses in healthy and prediabetic individuals.

Methods: A multi-centre study in the UK and the U.S. assessed the postprandial insulin, glucose and triglyceride responses to a dietary challenge (50g fat and 85g carbohydrate) in the clinic. The inter-individual variability in postprandial glycemic responses was then measured over 2 weeks for isocaloric meals of different macronutrient content using a continuous glucose monitor (CGM). Interim analyses of the 30- and 120-min insulin rises and meal content contributions to the incremental glucose area under the curve (iAUC) were performed in 573 individuals (age 47.5 (19-66) years, BMI 25.7 (17-53) kg/m2; F=76%; n=108 with HbA1c > 5.7% [prediabetic]).

Results: A machine learning algorithm showed that 29% of variation in glucose iAUC of at home meals was explained by the meal’s macronutrient content. In clinic, the 30min insulin postprandial rise (strongly associated with same meal’s glucose iAUC r=0.39 p=1.25x10[-20]) was not correlated with at-home postprandial glucose iAUCs in healthy (r=-0.012 p=0.62) or prediabetic (r=-0.074 p=0.17) individuals after adjustment for age, sex and BMI. However, 2hr insulin rise was significantly associated in healthy (r=0.13 p=1.6 x 10[-7]) and prediabetic (r=0.22 p=3.2x10[-5]) individuals, explaining 15% of the variance in glucose iAUCs. This was the same for all meals regardless of macronutrient content.

Conclusions: The 2hr postprandial insulin rise is a predictor of glycemic responses to different meal types. Ongoing exploration in PREDICT I using additional environmental, genetic and microbiome variables should advance our ability to predict an individual’s response to food.