Background:
Nonalcoholic Fatty Liver Disease (NAFLD) and excess visceral adipose tissue (VAT) are associated with cardiovascular disease (CVD). Recent studies suggest that NAFLD and coronary artery calcification (CAC) are related independent of VAT. In a population-based cross-sectional sample of black and white adults free from prevalent liver or heart disease, we tested the hypothesis that NAFLD is associated with the presence of CAC and abdominal aortoiliac calcification (AAC) independent of VAT and other CVD risk factors.
Methods:
Participants from the Coronary Artery Risk Development in Young Adults study (Y25 exam) with concurrent computed tomography quantification of liver fat, CAC and AAC were included (n=2,163). NAFLD was defined as liver attenuation ≤ 40 Hounsfield Units after exclusion of other causes of liver fat (medication/alcohol use). Using the Agatston method, CAC/AAC presence was defined as a score > 0. Logistic regression models were used to calculate odds ratios and 95% confidence intervals.
Results:
Participant age was 49.9 (3.7) years and the sample was equally distributed by sex (55.6% female) and race (50.1% black). Mean BMI was 30.6 (7.1). The CAC and AAC prevalence was 26.5% and 49.6%. NAFLD prevalence was 9.6%. NAFLD participants were 50.1 (3.7) years old and more likely to be male (59.8% vs. 51.7%, p<0.0001), white (56.5% vs. 49.3%, p<0.05) and have the metabolic syndrome (70.1% vs. 22.6%, p<0.0001) than those with no NAFLD. They were also more likely to have CAC (37.2%) and AAC (60.9%) than those with no NAFLD (25.4% and 49.4%, respectively). In multivariable analyses adjusted for demographics and health behaviors, NAFLD was associated with the presence of CAC and AAC (Table 1). This association was attenuated after adjustment for CVD risk factors and VAT. Effect modification by race and sex was not statistically significant.
Conclusion:
In contrast to prior studies, our results suggest that the relationship between NAFLD and subclinical CVD is mediated by the presence of other CVD risk factors.
Histological changes in the liver of diabetic rats: A review of pathogenesis of nonalcoholic fatty liver disease in type 1 diabetes mellitus
