Background: Non-alcoholic fatty liver disease (NAFLD) is closely correlated to metabolic syndrome, which is a marker of increased cardiovascular risk. Aortic stiffness and intima media thickness (IMT) are independent prognostic factors of cardiovascular risk. We investigated whether NAFLD is associated with increased atherosclerotic damage.

Methods: 46 patients (mean age 55±13 yrs, 24M/22F) with increased serum alanine aminotransferase levels and abdominal ultrasound and/or biopsy evidence of NAFLD, and 40 age, gender, body-mass index, and cardiovascular risk factors adjusted controls were studied. Carotid-femoral pulse wave velocity (PWV), an established index of aortic stiffness, was calculated using a validated noninvasive device (Complior^®). Higher values of PWV indicate stiffer aorta and vice versa. Mean IMT of common carotid arteries was determined as a marker of generalized early atherosclerosis using B-mode ultrasound imaging.

Results: NAFLD subjects had significantly increased carotid-femoral PWV (8.5±1.7 vs 7.9±1.5m/s, p < 0.05) and mean value of carotid IMT (0.98±0.3 vs 0.77±0.2 mm, p < 0.05) compared to controls. Systolic, diastolic and pulse pressure were not different among the two groups. Interestingly enough, patients with increasing fibrosis stage (ALT/AST ratio of greater than 1, n = 21) had increased carotid-femoral PWV and mean carotid IMT compared to patients with ratio lower than 1, after adjusting for age and systolic blood pressure (9.2±1.6 vs. 8.2±1.5m/s, p < 0.01 and 1.08±0.37 vs 0.83±0.21 mm, p < 0.05, respectively).

Conclusions: Patients with NAFLD have increased aortic stiffness and IMT, indicating both functional and structural changes in large arteries. These findings are important to further characterize the increase of cardiovascular risk in such patients.