Objectives: To assess the relationship between nonalcoholic fatty liver disease (NAFLD) and arterial stiffness in nondiabetic, nonhypertensive individuals with and without metabolic syndrome (MetS). Methods: Hepatic ultrasound and brachial-ankle pulse wave velocity (baPWV) were investigated in 4,467 individuals. The subjects were classified into normal PWV and increased PWV (>= 1,366 cm/s) groups, and divided into 2 groups (non-NAFLD vs. NAFLD groups) and 3 groups (non-, mild and moderate-to-severe NAFLD groups), respectively. Results: The overall prevalence of NAFLD was 37.3% and the NAFLD group had higher levels of baPWV (control vs. NAFLD, 1,363 +/- 210.3 vs. 1,388 +/- 235.9 cm/s, p < 0.001). On multivariate regression analysis, NAFLD was independently associated with increased baPWV (>= 1,366 cm/s), irrespective of multiple covariates (OR 1.237 and 95% CI 1.050-1.458). Subgroup analyses revealed that there was a significant association between NAFLD and baPWV only in individuals without MetS (OR 1.267 and 95% CI 1.065-1.507). The multivariate linear regression models for the overall study population and for individuals without MetS also revealed a significant association between NAFLD and the absolute value of baPWV; however, the result for individuals with MetS did not. Conclusions: Our results indicate that the presence and the degree of NAFLD are associated with arterial stiffness in nonhypertensive, nondiabetic individuals, especially in those individuals without MetS. Copyright (C) 2012 S. Karger AG, Basel