Background: Pericardial fat may be an important mediator of metabolic risk. Correlations with cardiovascular disease risk factors and vascular calcification in a community-based sample are lacking. We sought to examine associations between pericardial fat, metabolic risk factors, and vascular calcification.
Methods and results: Participants free of cardiovascular disease from the Framingham Heart Study (n=1155, mean age 63 years, 54.8% women) who were part of a multidetector computed tomography study underwent quantification of intrathoracic fat, pericardial fat, visceral abdominal fat (VAT), coronary artery calcification, and aortic artery calcification. Intrathoracic and pericardial fat volumes were examined in relation to body mass index, waist circumference, VAT, metabolic risk factors, coronary artery calcification, and abdominal aortic calcification. Intrathoracic and pericardial fat were directly correlated with body mass index (r=0.41 to 0.51, P<0.001), waist circumference (r=0.43 to 0.53, P<0.001), and VAT (r=0.62 to 0.76, P<0.001). Both intrathoracic and pericardial fat were associated with higher triglycerides (P<0.0001), lower high-density lipoprotein (P<0.0001), hypertension (P<0.0001 to 0.01), impaired fasting glucose (P<0.0001 to 0.001), diabetes mellitus (P=0.0005 to 0.009), and metabolic syndrome (P<0.0001) after multivariable adjustment. Associations generally persisted after additional adjustment for body mass index and waist circumference but not after adjustment for VAT (all P>0.05). Pericardial fat, but not intrathoracic fat, was associated with coronary artery calcification after multivariable and VAT adjustment (odds ratio 1.21, 95% confidence interval 1.005 to 1.46, P=0.04), whereas intrathoracic fat, but not pericardial fat, was associated with abdominal aortic calcification (odds ratio 1.32, 95% confidence interval 1.03 to 1.67, P=0.03).
Conclusions: Pericardial fat is correlated with multiple measures of adiposity and cardiovascular disease risk factors, but VAT is a stronger correlate of most metabolic risk factors. However, intrathoracic and pericardial fat are associated with vascular calcification, which suggests that these fat depots may exert local toxic effects on the vasculature.