BACKGROUND and AIMS: Non-alcoholic fatty liver disease confers increased risk for cardiovascular disease, including heart failure (HF), for reasons that remain unclear. Possible pathways could involve an association of liver fat with cardiac structural or functional abnormalities even after accounting for body size. METHODS: We analysed N = 2356 Framingham Heart Study participants (age 52 +/- 12 years, 52% women) who underwent echocardiography and standardized computed tomography measures of liver fat. RESULTS: In cross-sectional multivariable regression models adjusted for age, gender, cohort and cardiovascular risk factors, liver fat was positively associated with left ventricular (LV) mass (beta = 1.45; 95% confidence interval (CI): 0.01, 2.88), LV wall thickness (beta = 0.01; 95% CI: 0.00, 0.02), mass volume ratio (beta = 0.02; 95% CI 0.01, 0.03), mitral peak velocity (E) (beta = 0.83; 95% CI 0.31, 1.36) and LV filling pressure (E/e' ratio) (beta = 0.16; 95% CI 0.09, 0.23); and inversely associated with global systolic longitudinal strain (beta = 0.20, 95% CI 0.07, 0.33), diastolic annular velocity (e') (beta = -0.12; 95% CI - 0.22, -0.03), and E/A ratio (beta = -0.01; 95% CI - 0.02, -0.00). After additional adjustment for body mass index (BMI), statistical significance was attenuated for all associations except for that of greater liver fat with increased LV filling pressure, a possible precursor to HF (beta = 0.11; 95% CI 0.03, 0.18). CONCLUSION: Increased liver fat was associated with multiple subclinical cardiac dysfunction measures, with most of associations mediated by obesity. Interestingly, the association of liver fat and LV filling pressure was only partially mediated by BMI, suggesting a possible direct effect of liver fat on LV filling pressure. Further confirmatory studies are needed.

BACKGROUND: Visceral adipose tissue (VAT) and fatty liver differ in their associations with cardiovascular risk compared with subcutaneous adipose tissue (SAT). Several biomarkers have been linked to metabolic derangements and may contribute to the pathogenicity of fat depots. We examined the association between fat depots on multidetector computed tomography and metabolic regulatory biomarkers. METHODS AND RESULTS: Participants from the Framingham Heart Study (n=1583, 47% women) underwent assessment of SAT, VAT, and liver attenuation. We measured circulating biomarkers secreted by adipose tissue or liver (adiponectin, leptin, leptin receptor, fatty acid binding protein 4, fetuin-A, and retinol binding protein 4). Using multivariable linear regression models, we examined relations of fat depots with biomarkers. Higher levels of fat depots were positively associated with leptin and fatty acid binding protein 4 but negatively associated with adiponectin (all P < 0.001). Associations with leptin receptor, fetuin-A, and retinol binding protein 4 varied according to fat depot type or sex. When comparing the associations of SAT and VAT with biomarkers, VAT was the stronger correlate of adiponectin (beta=-0.28 [women]; beta=-0.30 [men]; both P < 0.001), whereas SAT was the stronger correlate of leptin (beta=0.62 [women]; beta=0.49 [men]; both P < 0.001; P < 0.001 for comparing VAT versus SAT). Although fetuin-A and retinol binding protein 4 are secreted by the liver in addition to adipose tissue, associations of liver attenuation with these biomarkers was not stronger than that of SAT or VAT. CONCLUSIONS: SAT, VAT, and liver attenuation are associated with metabolic regulatory biomarkers with differences in the associations by fat depot type and sex. These findings support the possibility of biological differences between fat depots.

BACKGROUND: Excess accumulation of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) is associated with adverse levels of adipokines and cardiovascular disease risk. Whether fat quality is associated with adipokines has not been firmly established. This study examined the association between abdominal SAT and VAT density, an indirect measure of fat quality, with a panel of metabolic regulatory biomarkers secreted by adipose tissue or the liver independently of absolute fat volumes. METHODS AND RESULTS: We evaluated 1829 Framingham Heart Study participants (44.9% women). Abdominal SAT and VAT density was estimated indirectly by adipose tissue attenuation using computed tomography. Adipokines included adiponectin, leptin receptor, leptin, fatty acid-binding protein 4 (FABP-4), retinol-binding protein 4 (RBP-4), and fetuin-A. Fat density was associated with all the biomarkers evaluated, except fetuin-A. Lower fat density (ie, more-negative fat attenuation) was associated with lower adiponectin and leptin receptor, but higher leptin and FABP-4 levels (all P < 0.0001). SAT density was inversely associated with RPB-4 in both sexes, whereas the association between VAT density and RPB-4 was only observed in men (P < 0.0001). In women, after additional adjustment for respective fat volume, SAT density retained the significant associations with adiponectin, leptin, FABP-4, and RBP-4; and VAT density with adiponectin only (all P<0.0001). In men, significant associations were maintained upon additional adjustment for respective fat volume (P < 0.005). CONCLUSIONS: Lower abdominal fat density was associated with a profile of biomarkers suggestive of greater cardiometabolic risk. These observations support that fat density may be a valid biomarker of cardiometabolic risk.