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Experimental Diabetes Research
Volume 2012, Article ID 851487, 8 pages
http://dx.doi.org/10.1155/2012/851487
Clinical Study

Acute Hyperglycemia Does Not Impair Microvascular Reactivity and Endothelial Function during Hyperinsulinemic Isoglycemic and Hyperglycemic Clamp in Type 1 Diabetic Patients

13rd Department of Internal Medicine, 1st Faculty of Medicine, Charles University, U Nemocnice 1, 12800 Prague, Czech Republic
2Department of Hematology, 1st Faculty of Medicine, Charles University, U Nemocnice 2, 12800 Prague, Czech Republic

Received 13 July 2011; Accepted 22 September 2011

Academic Editor: Bernard Portha

Copyright © 2012 Eva Horová et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Aims. The aim of this study was to evaluate the effect of acute glycemia increase on microvasculature and endothelium in Type 1 diabetes during hyperinsulinemic clamp. Patients and Methods. Sixteen patients (  yrs) without complications were examined during iso- and hyperglycemic clamp (glucose increase 5.5 mmol·L−1). Insulin, lipid parameters, cell adhesion molecules and fibrinogen were analyzed. Microvascular reactivity (MVR) was measured by laser Doppler flowmetry. Results. Maximum perfusion and the velocity of perfusion increase during PORH were higher in hyperglycemia compared to baseline ( versus  PU, , and versus  PU·s−1, , resp.). Time to the maximum perfusion during TH was shorter and velocity of perfusion increase during TH higher at hyperglycemia compared to isoglycemic phase ( versus  s, , and versus  PU·s−1, , resp.). An inverse relationship was found between insulinemia and the time to maximum perfusion during PORH ( , ). Conclusion. Acute glycemia did not impair microvascular reactivity in this clamp study in Type 1 diabetic patients. Our results suggest that insulin may play a significant role in the regulation of microvascular perfusion in patients with Type 1 diabetes through its vasodilation effect and can counteract the effect of acute glucose fluctuations.