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This Article Full Text Full Text (PDF) All Versions of this Article: 294/2/E261    most recent 00676.2007v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Lee, S. Articles by Quon, M. J. PubMed PubMed Citation Articles by Lee, S. Articles by Quon, M. J.

Comparison between surrogate indexes of insulin sensitivity and resistance and hyperinsulinemic euglycemic clamp estimates in mice

¹Diabetes Unit, National Center for Complementary and Alternative Medicine, National Institutes of Health, Bethesda, Maryland; ²Division of Biostatistics, Center for Devices and Radiological Health, United States Food and Drug Administration, Rockville, Maryland; ³Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania

Submitted 22 October 2007 ; accepted in final form 9 November 2007

Insulin resistance contributes to the pathophysiology of diabetes, obesity, and their cardiovascular complications. Mouse models of these human diseases are useful for gaining insight into pathophysiological mechanisms. The reference standard for measuring insulin sensitivity in both humans and animals is the euglycemic glucose clamp. Many studies have compared surrogate indexes of insulin sensitivity and resistance with glucose clamp estimates in humans. However, regulation of metabolic physiology in humans and rodents differs and comparisons between surrogate indexes and the glucose clamp have not been directly evaluated in rodents previously. Therefore, in the present study, we compared glucose clamp-derived measures of insulin sensitivity (GIR and SI_Clamp) with surrogate indexes, including quantitative insulin-sensitivity check index (QUICKI), homeostasis model assessment (HOMA), 1/HOMA, log(HOMA), and 1/fasting insulin, using data from 87 mice with a wide range of insulin sensitivities. We evaluated simple linear correlations and performed calibration model analyses to evaluate the predictive accuracy of each surrogate. All surrogate indexes tested were modestly correlated with both GIR and SI_Clamp. However, a stronger correlation between body weight per se and both GIR and SI_Clamp was noted. Calibration analyses of surrogate indexes adjusted for body weight demonstrated improved predictive accuracy for GIR [e.g., R = 0.68, for QUICKI and log(HOMA)]. We conclude that linear correlations of surrogate indexes with clamp data and predictive accuracy of surrogate indexes in mice are not as substantial as in humans. This may reflect intrinsic differences between human and rodent physiology as well as increased technical difficulties in performing glucose clamps in mice.

calibration model; quantitative insulin-sensitivity check index