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This Article Full Text Full Text (PDF) All Versions of this Article: 297/4/R1195    most recent 90851.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Christoffersen, B. Articles by Pacini, G. PubMed PubMed Citation Articles by Christoffersen, B. Articles by Pacini, G.

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Evaluation of different methods for assessment of insulin sensitivity in Göttingen minipigs: introduction of a new, simpler method

¹GLP-1 and Obesity Pharmacology and ²Insulin Pharmacology, Novo Nordisk A/S, Måløv, Denmark; and ³Metabolic Unit, Institute of Biomedical Engineering, Consiglio Nazionale delle Ricerche, Padua, Italy

Submitted October 21, 2008 ; accepted in final form August 19, 2009

The use of animal models in diabetes research requires reliable tests for evaluation of insulin sensitivity and β-cell function. Minipigs are being increasingly used in metabolic research, and the aim of this study was to compare different tests and indexes for evaluation of insulin sensitivity and β-cell function in Göttingen minipigs. Hyperinsulinemic, isoglycemic clamp, intravenous (IVGTT) and oral glucose tolerance tests (OGTT), and a modified insulin tolerance test were performed in minipigs fed either low- or high-energy diet. Furthermore, the reproducibility of IVGTT-derived parameters was assessed. Previously described insulin sensitivity indexes [steady-state glucose infusion rate/glucose concentration/insulin concentration from clamp (M/G/I); oral glucose insulin sensitivity (OGIS) and ISI_comp from OGTT; S_I from minimal model analysis of IVGTT; and quantitative insulin sensitivity check index from fasting values] were calculated together with an insulin sensitivity index from the modified insulin tolerance test (ISI_ITT) and a new simple index (S2) derived from the first 30 min of the IVGTT. β-Cell function was assessed from the IVGTT and the OGTT. Reproducibility of the IVGTT-derived parameters was calculated as median intraindividual coefficient of variation (CV%).M/G/I correlated significantly only with S2 (P < 0.05, r = 0.54). S2 furthermore correlated with S_I (P < 0.001, r = 0.81), ISI_ITT (P < 0.001, r = 0.57), and the two indexes from OGTT, ISI_comp (P < 0.001, r = 0.78) and OGIS (p < 0.05, r = 0.48). No correlation was found between β-cell function indexes from OGTT and IVGTT. The median CV% of the new S2 index was 13. In conclusion, the new simple index of insulin sensitivity, S2, was revealed to be useful for evaluation of insulin sensitivity in pigs.

glucose tolerance; β-cell function; intravenous glucose tolerance test; oral glucose tolerance test; clamp