Associations between nonalcoholic fatty liver disease and subclinical atherosclerosis in middle-aged adults: The coronary artery risk development in young adults study

Objective: Non-alcoholic fatty liver disease (NAFLD) is an obesity-related condition associated with cardiovascular mortality. Yet, whether or not NAFLD is independently related to atherosclerosis is unclear. In a population-based cross-sectional sample of middle-aged adults free from liver or heart disease, we tested the hypothesis that NAFLD is associated with subclinical atherosclerosis (coronary artery (CAC) and abdominal aortic calcification (AAC)) independent of obesity. Methods: Participants from the Coronary Artery Risk Development in Young Adults study with CT quantification of liver fat, CAC and AAC were included (n=2424). NAFLD was defined as liver attenuation ≤40 Hounsfield Units after exclusion of other causes of liver fat. CAC and AAC presence was defined as Agatston score >0. Results: Mean participant age was 50.1±3.6 years, (42.7% men, 50.0% black) and BMI was 30.6±7.2kg/m². The prevalence of NAFLD, CAC, and AAC was 9.6%, 27.1%, and 51.4%. NAFLD participants had increased prevalence of CAC (37.9% vs. 26.0%, p<0.001) and AAC (65.1% vs. 49.9%, p<0.001). NAFLD remained associated with CAC (OR, 1.33; 95% CI, 1.001-1.82) and AAC (OR, 1.74; 95% CI, 1.29-2.35) after adjustment for demographics and health behaviors. However, these associations were attenuated after additional adjustment for visceral adipose tissue (CAC OR, 1.05; 95% CI, 0.74-1.48, AAC OR=1.20; 95% CI, 0.86-1.67). There was no interaction by race or sex. Conclusion: In contrast to prior research, these findings suggest that obesity attenuates the relationship between NAFLD and subclinical atherosclerosis. Further studies evaluating the role of NAFLD duration on atherosclerotic progression and cardiovascular events are needed.