Purpose: The purpose was to investigate whether the metabolic syndrome was associated with measures of arterial stiffness, flow mediated dilatation (FMD), carotid intima-media thickness (IMT) and carotid plaques (CP) in middle-aged subjects without and with MetS.

Methods: 186 asymptomatic volunteers (40–65 years old, 86 males) without clinically overt cardiovascular disease were examined. MetS was defined according to the International Diabetes Federation consensus. The prevalence of MetS was 32.8 %. Augmentation index (AIx) and carotid-radial pulse wave velocity (PWV) as measures of arterial stiffness were assessed by applanation tonometry. FMD as the measure of endothelial function was determined using high resolution B-mode ultrasonography. IMT and CP were assessed by high resolution B-mode ultrasonography.

Results: PWV was significantly elevated in the MetS group (9.20 ± 1.08 vs. 23.30 ± 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 patients with and without MetS (23.97 ± 8.08 vs. 23.30 ± 9.75, P = 0.248). The presence of MetS was significant (P = 0.005) when predicting values 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 MetS was a significant predictor of the presence of carotid plaques (OR = 0.341, 95 % CI [0.173–0.673], P = 0.002).

Conclusions: Metabolic syndrome is associated with increased arterial stiffness, decreased flow mediated dilatation, increased carotid intima-media thickening and with the presence of carotid plaques.