Evaluation of postprandial total triglycerides within the TIGG model for characterizing postprandial response of glucose, insulin, and GLP‐1

Abstract

The TIGG model is the first model to integrate glucose and insulin regulation, incretin effect, and triglyceride (TG) response in the lipoprotein subclasses of chylomicrons and VLDL‐V6. This model described the response following a high‐fat meal in individuals who are lean, obese, and very obese and provided insights into the possible regulation of glucose homeostasis in the extended period following a meal. Often, total TGs are analyzed within clinical studies, instead of lipoprotein subclasses. We extended the existing TIGG model to capture the observed total TGs and determined if this model could be used to predict the postprandial TG response of chylomicron and VLDL‐V6 when only total TGs are available. To assess if the lipoprotein distinction was important for the model, a second model (tTIGG) was developed using only the postprandial response in total TGs, instead of postprandial TG response in chylomicrons and VLDL‐V6. The two models were compared on their predictability to characterize the postprandial response of glucose, insulin, and active GLP‐1. Both models were able to characterize the postprandial TG response in individuals who are lean, obese, or very obese following a high‐fat meal. The extended TIGG model resulted in a better model fit of the glucose data compared to the tTIGG model, indicating that chylomicron and VLDL‐V6 provided additional information compared to total TGs. Furthermore, the expanded TIGG model was able to predict the postprandial TG response of chylomicrons and VLDL‐V6 using the total TGs and could therefore be used in studies where only total TGs were collected.

The chylomicron saga: time to focus on postprandial metabolism

“…Reduced lipid absorption, decreased CM secretion, and/or improved clearance from the circulation are only a few possible pathways that could explain improvements in postprandial lipemia with GLP-1R agonists and DPP-4 inhibitors. Exenatide (a GLP-1 agonist) or a GLP-1 infusion can also regulate intestinal lipoprotein synthesis without affecting changes in gastric emptying, as was shown by bypassing the stomach ( 61 , 130 – 133 ).…”

“…According to research, when GLP-1 activity is sustained, the effects of GLP-1 take precedence over those of GLP-2 under physiological settings. However, the overall impact of GLP-1 and GLP-2 on intestinal lipid transport is still unknown and should be clarified ( 69 , 130 , 131 , 133 ).…”

“…For the past 30 years, studies on human subjects have looked at postprandial lipid reactions to meals high in fat. The amount of fat taken, alcohol use before or during the meal, the presence of other macronutrients, the presence of fiber, and physical activity are just a few of the variables that influence how the TG reacts to a meal that contains fat ( 18 , 70 , 133 , 141 ).…”