Differential effect of metabolic syndrome on various parameters of arterial stiffness

Metabolic syndrome (MetSy) is associated with a high risk of cardiovascular complications. Arterial stiffness is an independent predictor of cardiovascular morbidity and mortality. This study investigated the effect of individual MetSy risk factors on central and peripheral parameters of aortic stiffness. In the Czech post-MONICA study, we measured aortic pulse-wave velocity (aPWV), lower extremity pulse-wave velocity (lePWV), augmentation index (AIx) and central augmentation pressure (cAP) in 936 subjects. Based on the definition of MetSy, we divided subjects according to number of risk factors. We used univariate and multivariate linear regression analysis to assess the association between number of risk factors and aPWV, lePWV, AIx and cAP. In analyses adjusted for age, gender, heart rate and mean arterial pressure, aPWV was higher in subjects with MetSy (MetSy+ group) than in those without (MetSy + group) (8.3 vs. 7.7 m/s; p < 0.0001), but lePWV was not significantly different between the groups (11.0 vs. 11.2 m/s; p = 0.2037). After adjustment for covariates, AIx in MetSy+ was lower than in MetSy- respondents (143.2 vs. 146.8; p = 0.014). In adjusted analysis, aPWV rose with increasing number of MetSy risk factors (7.3 ± 0.1 vs. 9.0 ± 0.1 m/s; p for trend < 0.0001). The number of MetSy risk factors did not affect lePWV (p = 0.11). AIx decreased with higher number of MetSy risk factors (148.3 vs. 141.5; p = 0.020). This finding confirms the fact that PWV and AIx may have different associations with risk factors and AIx should not be used as an isolated parameter of arterial stiffness. The individual MetSy risk factors have only a small effect on lower extremity arterial stiffness.