Novel fat depot shows links with CVD risk markers
MedWire News: The volume of fat surrounding the thoracic aorta is associated with measures of adiposity, metabolic risk factors, and arterial calcification, US researchers have found.
They suggest that thoracic peri-aortic fat, by secreting paracrine and pro-inflammatory factors, may play a role in the pathogenesis of both local and distant atherosclerotic vascular disease.
Caroline Fox (Brigham and Women’s Hospital, Boston, Massachusetts) and colleagues analyzed data on 1067 participants from the Framingham Offspring Study, an observational cohort study involving spouses and children of the original Framingham Heart Study participants.
All participants were free of cardiovascular disease at baseline. Body composition and vascular calcification were assessed using chest and abdominal multi-detector computed tomography (CT).
Writing in the journal Atherosclerosis, Fox et al describe a new depot of body fat, termed “thoracic peri-aortic fat,” which was quantifiable with high reproducibility using CT. The mean volume of thoracic peri-aortic fat was 11.9 cm³ in women and 20.3 cm³ in men.
Significantly, the volume of this novel fat depot was associated with most cardiovascular risk factors, and the associations remained significant after adjustment for age, body mass index, and waist circumference.
Thoracic peri-aortic fat also correlated with coronary artery calcification and abdominal aortic calcification, with odds ratios of 1.31 and 1.70, respectively, per standard deviation increase in thoracic peri-aortic fat volume. Again, these associations remained significant in multivariable models.
Fox and colleagues say that they have identified a novel body fat depot that correlates with visceral adipose tissue, a well-established fat depot with important implications for cardiovascular disease. Thoracic peri-aortic fat also correlated with abdominal aortic and coronary calcification and with overall cardiovascular risk.
“The association between thoracic peri-aortic fat and both abdominal aortic and coronary calcification in the absence of an association with local thoracic aortic calcification is of interest and should stimulate interest in the expression profiles of this fat depot,” they write.
“Future research should aim to identify differences in cytokine expression profiles between fat depots that exhibit a local association with atherosclerosis and those that do not to identify potentially causative mediators.”
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By Joanna Lyford