Classical and model-based estimates of beta-cell function during a mixed meal vs. an OGTT in a population-based cohort

Rijkelijkhuizen, Josina M.; Girman, Cynthia J.; Mari, Andrea; Alssema, Marjan; Rhodes, Thomas; Nijpels, Giel; Kostense, Piet J.; Stein, Peter P.; Eekhoff, Elisabeth M.; Heine, Robert J.; Dekker, Jacqueline M.

doi:10.1016/j.diabres.2008.11.017

« Previous Next »Diabetes Research and Clinical Practice
Volume 83, Issue 2 , Pages 280-288, February 2009

Classical and model-based estimates of beta-cell function during a mixed meal vs. an OGTT in a population-based cohort

Josina M. Rijkelijkhuizen
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
- Corresponding author. Tel.: +31 20 4449831; fax: +31 20 4448181.
Cynthia J. Girman
- Merck & Co., Inc., Department of Epidemiology, Clinical and Quantitative Sciences, North Wales, PA, USA
Andrea Mari
- Institute of Biomedical Engineering, National Research Council, Padua, Italy
Marjan Alssema
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
Thomas Rhodes
- Merck & Co., Inc., Department of Epidemiology, Clinical and Quantitative Sciences, North Wales, PA, USA
Giel Nijpels
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
- Department of General Practice, VU University Medical Center, Amsterdam, The Netherlands
Piet J. Kostense
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
- Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands
Peter P. Stein
- Merck & Co., Clinical Research, Inc., Clinical and Quantitative Sciences, Rahway, NJ, USA
Elisabeth M. Eekhoff
- Department of Endocrinology, VU University Medical Center, Amsterdam, The Netherlands
Robert J. Heine
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
- Department of Endocrinology, VU University Medical Center, Amsterdam, The Netherlands
Jacqueline M. Dekker
- EMGO Institute, VU University Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands

Received 13 February 2008; received in revised form 7 November 2008; accepted 12 November 2008. published online 22 December 2008.

Abstract

This study compared classical and model-based beta-cell responses during an oral glucose tolerance test (OGTT) and a meal tolerance test (MTT) in a population-based cohort. Individuals with normal glucose metabolism (NGM, n=161), impaired glucose metabolism (IGM, n=19) and type 2 diabetes mellitus (DM, n=20) underwent a 75g-OGTT and an MTT (75g carbohydrates, 50g fat, 24g proteins). Classical estimates of beta-cell function (insulinogenic index and the ratio of areas under insulin and glucose curves) were calculated. Mathematical modelling was used to determine beta-cell glucose sensitivity, rate sensitivity and potentiation. Insulin sensitivity was characterized by three surrogate estimates. Both classical and model-based estimates of beta-cell function were higher during MTT than during OGTT (P<0.05). Regarding the model-based parameters, especially beta-cell sensitivity was increased following MTT as compared with OGTT (P<0.05). Both during OGTT and MTT, across most parameters describing beta-cell function, the largest reduction in beta-cell response occurred between IGM and DM, while the largest reduction in insulin sensitivity occurred between NGM and IGM. We conclude that beta-cell response is stronger after a mixed meal than after an OGTT with equal carbohydrate quantity, both for classical and model-based parameters. The higher response was mostly explained by higher beta-cell sensitivity during the meal.