Peri-aortic fat, cardiovascular disease risk factors, and aortic calcification: The Framingham Heart Study

Objective: Perivascular fat through the secretion of paracrine and pro-inflammatory mediators may play a role in obesity-mediated vascular disease. We sought to examine associations between adipose tissue depots immediately surrounding the thoracic aorta, metabolic risk factors, and vascular calcification. Methods: In participants free of cardiovascular disease (CVD) from the Framingham Heart Study Offspring cohort who underwent computed tomography (n= 1067, mean age 59 years, 56.1% women), thoracic peri-aortic fat depots were quantified. Visceral abdominal tissue (VAT) and calcification of the thoracic and abdominal aorta were also measured. Results: Peri-aortic fat depots were correlated with body mass index, waist circumference (WC), VAT (all p<. 0.0001), hypertension (p= 0.007), low HDL (p<. 0.0001), serum triglycerides (p<. 0.0001), impaired fasting glucose (p=0.005), and diabetes (p= 0.02). These associations generally remained significant after adjustment for BMI and WC (all p-values <. 0.05), but not after VAT adjustment. Thoracic aortic fat was associated with thoracic calcification in models containing VAT (OR 1.31, 95% CI 1.01-1.71, p= 0.04), but was not significant after adjustment for CVD risk factors (OR 1.16, 95% CI 0.88-1.51, p= 0.30). Thoracic aortic fat, however, was associated with abdominal aortic calcification (OR 1.48, 95% CI 1.11-1.98, p= 0.008) and coronary artery calcification (OR 1.47, 95% CI 1.09-1.98, p= 0.001) even in models including CVD risk factors and VAT. Conclusions: Thoracic peri-aortic fat is associated with measures of adiposity, metabolic risk factors, and coronary and abdominal aortic calcification.