Systemic assessment of arterial wall structure and function in metabolic syndrome

Metabolic syndrome (MetS) is thought to increase cardiovascular risk. The aim of this study was to investigate whether the MetS and its components are associated with parameters of arterial stiffness, flow mediated dilatation (FMD) of the brachial artery, carotid intima-media thickness (IMT) and the presence of carotid plaques (CP) in middle-aged subjects. One-hundred eighty-six asymptomatic volunteers (40-65 years-old, 86 males and 100 females) without clinically overt cardiovascular disease were examined. MetS was defined according to the International Diabetes Federation consensus. The prevalence of MetS was 32.8% (61 subjects). Augmentation index (Alx) and carotid-radial pulse wave velocity (PWV) as parameters of arterial stiffness were assessed by applanation tonometry. FMD (as endothelial function) was determined using high resolution B-mode ultrasonography, as were IMT and CP. PWV was significantly elevated in the MetS group (9.20 +/- 1.08 vs. 8.70 +/- 1.02, p = 0.003). FMD was significantly lower in the MetS group (5.32 vs. 6.45%, p = 0.018). There was no statistically significant difference in AIx between subjects with and without MetS (23.97 +/- 8.08 vs. 23.30 +/- 9.75, p = 0.248, respectively). Multiple regression analysis has shown that the presence of MetS was a significant (p = 0.005) determinant of PWV but not FMD. IMT* was higher in the MetS group (0.08 [0.07-0.1] vs. 0.07 [0.06-0.08] p < 0.001). The presence of arterial hypertension was related to AIx (R2 = 0.444, adjusted R2 = 0.434, p = 0.001) and PWV (R2 = 0.161, adjusted R2 = 0.152, coefficient p = 0.001). Furthermore, mean arterial pressure (MAP) itself was an independent predictor of AIx (R2 = 0.571, adjusted R2 = 0.562, p < 0.001) and PWV (R2 = 0.281, adjusted R2 = 0.269, p < 0.001). Glycemia had an impact on IMT (R2 = 0.027, adjusted R2 = 0.022, p = 0.026). The MetS was a significant predictor of the presence of carotid plaques (OR = 0.341, 95 % CI [0.173 - 0.673], p = 0.002). Blood pressure is the most important determinant of structure and function of arteries.