title: Bayesian two-compartment and classic single-compartment minimal models: comparison on insulin modified IVGTT and effect of experiment reduction.
abstract: Models describing plasma glucose and insulin concentration of an intravenous glucose tolerance test (IVGTT) allow a noninvasive cost-effective approach to estimate important indexes characterizing the efficiency of glucose-insulin control system, i.e., glucose effectiveness (S(G)) and insulin sensitivity (S(I)). To overcome some limitations of the classic single compartment minimal model (1CMM) of glucose kinetics , a two-compartment Bayesian minimal model (2CBMM) has been recently proposed for the standard IVGTT. This study aims to assess 2CBMM ability to describe the insulin-modified IVGTT (IM-IVGTT) which is the protocol of choice since it allows to study insulinopenic states. Both a full-length IM-IVGTT (240 min) as well as a reduced version (90 min) of it are studied. Results of the maximum a posteriori identification of IM-IVGTT (240 min) in 13 normals agree with those of standard IVGTT, i.e., a 42% decrease (P < 0.002) of S(G) and a 13% increase (P < 0.006) of S(I) with respect to ICMM. When identified from IM-IVGTT (90 min), 2CBMM not only provides S(G) and S(I) estimates 46% lower (P < 0.002) and 41% higher (P < 0.002) than 1CMM ones respectively, but also seems to overcome some limitations of the 240 min-based identification that probably arise because the minimal model is unable to properly account for the hyperglycemic hormonal response taking place in the second half of IM-IVGTT.
authors.affiliation: Department of Information Engineering, University of Padova, 35131 Padova, Italy. tam@dei.unipd.it
authors.forename: Tiziano
authors.initials: T
authors.lastname: Callegari
authors.forename: Andrea
authors.initials: A
authors.lastname: Caumo
authors.forename: Claudio
authors.initials: C
authors.lastname: Cobelli
mesh_terms: D001499:Bayes Theorem; D001786:Blood Glucose / Q000032:analysis* / Q000378:metabolism*; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000032:analysis; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000008:administration & dosage / Q000097:blood* / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D015233:Models, Statistical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose