Classical and model-based estimates of beta-cell function during a mixed meal vs. an OGTT in a population-based cohort.
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 75 g-OGTT and an MTT (75 g carbohydrates, 50 g fat, 24 g 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.
Rijkelijkhuizen
Josina M
JM
EMGO Institute, VU University Medical Center, Amsterdam, The Netherlands. j.rijkelijkhuizen@vumc.nl
Girman
Cynthia J
CJ
Mari
Andrea
A
Alssema
Marjan
M
Rhodes
Thomas
T
Nijpels
Giel
G
Kostense
Piet J
PJ
Stein
Peter P
PP
Eekhoff
Elisabeth M
EM
Heine
Robert J
RJ
Dekker
Jacqueline M
JM
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D015331:Cohort Studies; D045424:Complex Mixtures / Q000494:pharmacology*; D005260:Female; D005502:Food; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011153:Population
D001786:Blood Glucose; D045424:Complex Mixtures; D007328:Insulin; D005947:Glucose