HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Online-Only Appendix All Versions of this Article: dc07-0422v1 30/9/2374    most recent Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Anderwald, C. Articles by Krebs, M. Search for Related Content PubMed PubMed Citation Articles by Anderwald, C. Articles by Krebs, M. Social Bookmarking                What's this?

Clamp-like Index: a Novel, Highly Sensitive Insulin Sensitivity Index to Calculate Hyperinsulinemic Clamp Glucose Infusion Rates from Oral Glucose Tolerance Test in Nondiabetic Humans

¹ Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Austria
² Department of Clinical Pharmacology, Medical University of Vienna, Austria
³ 3^rd Medical Department of Metabolic Diseases and Nephrology, Hietzing Hospital, Vienna, Austria
⁴ Karl Landsteiner Institute of Metabolic Diseases and Nephrology, Hietzing Hospital, Vienna, Austria
⁵ Department of Surgery, Medical University of Vienna, Austria
⁶ Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padova, Italy

christian-heinz.anderwald{at}meduniwien.ac.at

ABSTRACT

Objective.: Insulin resistance (IR), the underlying pathophysiological mechanism of the metabolic syndrome, could predict not only type-2 diabetes (T2DM) development, but also cardiovascular disease. Thus, precise IR measurement in individuals at risk for metabolic diseases would support clinical risk stratification. However, the "gold-standard" to measure IR, the hyperinsulinemic clamp-test, is too labor-intensive to be performed in large clinical studies/settings.

Research Design and Methods.: Using plasma glucose and C-peptide concentrations from oral glucose tolerance tests (oGTTs), we developed the novel "clamp-like index" (CLIX) for insulin sensitivity calculation, and compared CLIX to clamp glucose infusion rates (100-120min) (GIR_100-120min). We evaluated CLIX in eighty-nine nondiabetic subjects (f/m=58/31, aged:45±1years, BMI=27.5±0.8kg·m^-2) who underwent frequently-sampled three-hour-(75g)-oGTTs and two-hour hyperinsulinemic-(40mU·min^-1·m^-2)-isoglycemic clamp-tests.

Results.: CLIX, calculated as serum creatinine(x0.85 if male)/(mean AUC_glucosexmean AUC_C-peptide)x6600, highly correlated (r=0.670, p<10^-12) with and was comparable to clamp GIRs_100-120min.

In subgroup analyses, GIRs_100-120min were lower (p<0.005) in T2DM-offspring (OFF) (6.2±0.7 mg·min^-1·kg^-1) than in gender-, age- and BMI-matched subjects without T2DM family history (NOFF) (8.6±0.5 mg·min^-1·kg^-1), which was also reflected by CLIX (OFF:6.4±0.6 vs. NOFF:9.0±0.5, p<0.002). When compared to normal-weight subjects (GIR:8.8±0.4 mg·min^-1·kg^-1; CLIX:9.0±0.5), both GIRs_100-120min and CLIX of obese (5.2±0.9 mg·min^-1·kg^-1; 5.7±0.9) and morbid obese (2.4±0.4 mg·min^-1·kg^-1; 3.3±0.5) humans were lower (each p<0.02).

Conclusion:CLIX, a novel index obtained from plasma oGTT glucose and C-peptide levels and serum creatinine without inclusion of anthropometrical measures to calculate insulin sensitivity in nondiabetic humans, highly correlates with clamp GIRs and reveals even slight insulin sensitivity alterations over a broad BMI-range as sensitively as the hyperinsulinemic clamp-test.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Anderwald-Stadler, M. Krebs, M. Promintzer, M. Mandl, M. G. Bischof, P. Nowotny, T. Kastenbauer, A. Luger, R. Prager, and C. Anderwald Plasma obestatin is lower at fasting and not suppressed by insulin in insulin-resistant humans Am J Physiol Endocrinol Metab, November 1, 2007; 293(5): E1393 - E1398. [Abstract] [Full Text] [PDF]