Microvascular research
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Microvascular research · May 2008
Serum levels of soluble form of receptor for advanced glycation end products (sRAGE) are positively associated with circulating AGEs and soluble form of VCAM-1 in patients with type 2 diabetes.
We have recently found that soluble form of receptor for advanced glycation end products (sRAGE) levels are positively associated with inflammatory biomarkers and the presence of coronary artery disease (CAD) in type 2 diabetic patients. Since advanced glycation end products (AGEs) up-regulate RAGE expression and endogenous sRAGE could be generated from the cleavage of cell surface RAGE, it is conceivable that sRAGE is positively associated with circulating AGEs levels in diabetes. In this study, we examined whether sRAGE were correlated to circulating levels of AGEs and soluble forms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in patients with type 2 diabetes. ⋯ Multiple regression analysis revealed that serum levels of AGEs and sVCAM-1 were independently correlated with sRAGE. This study demonstrated that serum levels of sRAGE were positively associated with circulating AGEs and sVCAM-1 levels in type 2 diabetic patients. Our present observations suggest sRAGE level may be elevated in response to circulating AGEs, thus being a novel marker of vascular injury in patients with type 2 diabetes.
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Microvascular research · May 2008
Normal sublingual microcirculation during painful crisis in sickle cell disease.
Obstruction of the microcirculation is the most important cause of painful crisis in sickle cell disease (SCD). Extensive microvascular obstruction has been observed in mouse models of SCD. A technique to determine the extent of the microcirculatory obstructions in humans may be helpful in the clinical setting and for research purposes. ⋯ The mean MFI of patients with SCD during steady state (2.7+/-0.1) and the mean MFI of the controls (2.7+/-0.1) were not different from the mean MFI during painful crisis. During painful crisis irregular microvascular perfusion, expressed by the distribution width of the microvascular blood flow velocity, correlated negatively (r=-0.484; P=0.002) with hemoglobin concentration. We conclude that sublingual microcirculatory blood flow velocity is not disturbed in sickle cell patients during painful crisis.
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Microvascular research · May 2008
Impaired flow-mediated vasodilation in type 2 diabetes: lack of relation to microvascular dysfunction.
A reduced availability of nitric oxide (NO) is an important feature of endothelial dysfunction occurring early in the course of type 2 diabetes. The measurement of flow-mediated dilation (FMD) of the brachial artery after forearm ischemia is supposed to be a non-invasive method to assess endothelial production and release of NO. The impairment of reactive hyperemia due to microvascular dysfunction in diabetes might cause an insufficient increase in shear stress stimulating the endothelial NO release, thus leading to an underestimation of FMD. ⋯ FMD% was not related to CBV% (r=0.14; p=0.139). The lack of an association between the reduction of endothelium-dependent vasodilation of the brachial artery and the impairment of postocclusive microvascular hyperemia observed in the present study contradicts the assumption that a reduced FMD is only the consequence of an impaired reactive hyperemia due to microvascular dysfunction. It also lends support to the suggestion that endothelial dysfunction in conduit vessels and impaired cutaneous microvascular responses to reactive hyperemia might at least partly develop independently due to several differences in their pathogenesis.