A Mechanistic Model of Intermittent Gastric Emptying and Glucose-Insulin Dynamics following a Meal Containing Milk Components

PLoS One. 2016 Jun 2;11(6):e0156443. doi: 10.1371/journal.pone.0156443. eCollection 2016.

Abstract

To support decision-making around diet selection choices to manage glycemia following a meal, a novel mechanistic model of intermittent gastric emptying and plasma glucose-insulin dynamics was developed. Model development was guided by postprandial timecourses of plasma glucose, insulin and the gastric emptying marker acetaminophen in infant calves fed meals of 2 or 4 L milk replacer. Assigning a fast, slow or zero first-order gastric emptying rate to each interval between plasma samples fit acetaminophen curves with prediction errors equal to 9% of the mean observed acetaminophen concentration. Those gastric emptying parameters were applied to glucose appearance in conjunction with minimal models of glucose disposal and insulin dynamics to describe postprandial glycemia and insulinemia. The final model contains 20 parameters, 8 of which can be obtained by direct measurement and 12 by fitting to observations. The minimal model of intestinal glucose delivery contains 2 gastric emptying parameters and a third parameter describing the time lag between emptying and appearance of glucose in plasma. Sensitivity analysis of the aggregate model revealed that gastric emptying rate influences area under the plasma insulin curve but has little effect on area under the plasma glucose curve. This result indicates that pancreatic responsiveness is influenced by gastric emptying rate as a consequence of the quasi-exponential relationship between plasma glucose concentration and pancreatic insulin release. The fitted aggregate model was able to reproduce the multiple postprandial rises and falls in plasma glucose concentration observed in calves consuming a normal-sized meal containing milk components.

MeSH terms

  • Animals
  • Blood Glucose
  • Gastric Emptying / physiology
  • Glucagon / metabolism
  • Glucose / metabolism*
  • Glycemic Index
  • Humans
  • Insulin / metabolism*
  • Meals
  • Milk / metabolism*
  • Models, Biological*
  • Postprandial Period

Substances

  • Blood Glucose
  • Insulin
  • Glucagon
  • Glucose

Grants and funding

The co-author Harma Berends is employed by Trouw Nutrition R&D, Boxmeer, The Netherlands, but this does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Trouw Nutrition R&D provided support in the form of salary for author Harma Berends, but did not have any additional role in the model design and evaluation, decision to publish, or final preparation of the manuscript. The specific role of this author is articulated in the ‘author contributions’ section.