Metabolic Syndrome Individuals With and Without Type 2 Diabetes Mellitus Present Generalized Vascular Dysfunction

Abstract

Objectives— The first objective of this study was to demonstrate differences within endothelial-dependent and endothelial-independent vasoreactivity in macro- and microcirculation beds among patients with metabolic syndrome (MetS) with and without type 2 diabetes mellitus (T2D) compared with healthy counterparts. The second objective was to determine relationships among the function of macro- and microvascular systems and abdominal adiposity, as well as inflammatory markers in the 3 groups. Approach and Results— Cross-sectional analyses of 53 patients with MetS without T2D and 25 with T2D, as well as aged 40 years and sex-matched healthy controls included microvascular (cutaneous blood flow measured with laser Doppler flowmetry in response to iontophoresis of acetylcholine and sodium nitroprusside), and macrovascular reactivity (flow-mediated dilation and nitrate-mediated dilation) along with anthropometric measures, plasma glucose, and insulin and inflammatory markers. Compared with controls, MetS participants showed depressed endothelial function of both micro- and macrocirculation beds. T2D in patients with MetS revealed an exacerbated vascular smooth muscle dysfunction in micro- and macrocirculation compared with MetS without T2D. Indices of micro- and macrocirculation were predominantly inversely related to abdominal fat and inflammatory markers. Conclusions— MetS was associated with endothelial-dependent and endothelial-independent dysfunction, affecting both the macro- and the microvascular systems. Participants with diabetes mellitus demonstrated the most severe smooth muscle dysfunction. The presence of central abdominal fat and systemic inflammation seems implicated in the pathogenesis of vascular dysfunctions in MetS.

Exercise Training Reverses Structural Microvascular Rarefaction and Improves Endothelium-Dependent Microvascular Reactivity in Rats with Diabetes

“…27 Microvascular endothelial reactivity assessment is essential for investigating the pathophysiology of diabetes and cardiovascular diseases. 29,30 In the present study, microvascular endothelial function was evaluated using LSCI, which represents an innovative approach to the noninvasive evaluation of microvascular endothelial function. 31-33 A major advantage of this technique is that the reproducibility of LSCI is superior to earlier procedures, such as laser Doppler flowmetry and laser Doppler imaging.…”

Impact of Diabetes Mellitus

“…Central adiposity, rather than changes in blood glucose, was found to be a predictor for this exacerbated vascular phenotype. 6 These two studies highlight the impact of diabetes on vascular cells in humans, and suggest that these cells are responsive to extracellular perturbations associated with the diabetic environment and that hyperglycemia is unlikely to be solely responsible for vascular dysfunction associated with diabetes.…”

Endothelial Functions

“…Bretón-Romero et al 61 showed that wingless-type family member 5a/c-jun N terminal kinase pathway contributed to endothelial dysfunction associated with diabetic patients. Walther et al 62 demonstrated that not only endothelium-dependent but also endotheliumindependent vasodilatations in both micro-and macrocirculation were impaired in association with systemic inflammation in patients with metabolic syndrome with diabetes mellitus.…”