Non-alcoholic fatty liver disease (NAFLD) is considered an independent risk factor for increased cardiovascular disease (CVD).
Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) cohort enrolled 6814 adults without prior CVD. We excluded 2,692 participants who had missing variables, heavy drinkers, history of steroid use and chronic liver disease. NAFLD was defined using non-contrast cardiac CT and a liver/spleen attenuation ratio (L/S) < 1. Arterial compliance and stiffness, was expressed as Distensibility coefficient and Young’s modulus. Common and internal carotid intima media thickness (IMT) and coronary artery calcium (CAC) > 0 were used as markers of subclinical CVD. A multivariate robust linear regression and logistic regression analysis was done to evaluate the association of NAFLD and this subclinical CVD markers.
RESULTS: Our analysis of 4,123 participants showed a NAFLD prevalence 17% (n=665), 55% were female with a mean age of 63 (±10) years, 39% white, 10% Chinese, 28% African American, and 23% were Hispanic. Individuals with NAFLD had Distensibility coefficient (10-3 mmHg-1) of 2.4 vs. 2.5 without NAFLD, p=0.05. CIMT (mm) was 0.88 in NAFLD vs. 0.87 without NAFLD, p=0.003. Multivariate linear regression analysis showed the presence of NAFLD was associated with both the common carotid and internal carotid IMT and logCAC. Logistic analysis only showed an independent association with CAC>0 (OR 1.44 95% CI 1.18, 1.75) and CIMT >1mm (OR 1.30 95% 1.08, 1.56). When stratified by race the association with CIMT >1mm was only significant among Caucasian whites (OR 1.37 95% 1.00, 1.90) and Hispanic (OR 1.53 95% 1.08, 2. 17) and CAC>0 was only significant among Hispanics (OR 1.52 95% 1.06, 2.19).
Conclusion: NAFLD is independently associated with Carotid IMT and coronary artery calcification in a multi-ethnic population. This study reaffirms the role of NAFLD in early atherosclerosis and provides opportunity to explore strategies for early screening for subclinical CVD and aggressive preventive therapies.