title: Evaluation of insulin sensitivity and beta-cell function indexes obtained from minimal model analysis of a meal tolerance test.
abstract: Modeling analysis of glucose, insulin, and C-peptide following a meal has been proposed as a means to estimate insulin sensitivity (S(i)) and beta-cell function from a single test. We compared the model-derived meal indexes with analogous indexes obtained from an intravenous glucose tolerance test (IVGTT) and hyperglycemic clamp (HGC) in 17 nondiabetic subjects (14 men, 3 women, aged 50 +/- 2 years [mean +/- SE], BMI 25.0 +/- 0.7 kg/m(2)). S(i) estimated from the meal was correlated with S(i) estimated from the IVGTT and the HGC (r = 0.59 and 0.76, respectively; P < 0.01 for both) but was approximately 2.3 and 1.4 times higher (P < 0.05 for both). The meal-derived estimate of the beta-cell's response to a steady-state change in glucose (static secretion index) was correlated with the HGC second-phase insulin response (r = 0.69; P = 0.002), but the estimated rate-of-change component (dynamic secretion index) was not correlated with first-phase insulin release from either the HGC or IVGTT. Indexes of beta-cell function obtained from the meal were significantly higher than those obtained from the HGC. In conclusion, insulin sensitivity and beta-cell indexes derived from a meal are not analogous to those from the clamp or IVGTT. Further work is needed before these indexes can be routinely used in clinical and epidemiological studies.
authors.affiliation: Medtronic MiniMed, 18000 Devonshire Street, Northridge, CA 91325, USA. garry.steil@Medtronic.com
authors.forename: Garry M
authors.initials: GM
authors.lastname: Steil
authors.forename: Chi-min
authors.initials: CM
authors.lastname: Hwu
authors.forename: Robert
authors.initials: R
authors.lastname: Janowski
authors.forename: Farzam
authors.initials: F
authors.lastname: Hariri
authors.forename: Sujata
authors.initials: S
authors.lastname: Jinagouda
authors.forename: Christine
authors.initials: C
authors.lastname: Darwin
authors.forename: Sameh
authors.initials: S
authors.lastname: Tadros
authors.forename: Kerstin
authors.initials: K
authors.lastname: Rebrin
authors.forename: Mohammed F
authors.initials: MF
authors.lastname: Saad
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D019518:Postprandial Period; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin