Periaortic fat deposition is associated with peripheral arterial disease: the Framingham heart study

Abstract

Background: Central obesity is associated with peripheral arterial disease, suggesting that ectopic fat depots may be associated with localized diseases of the aorta and lower-extremity arteries. We hypothesized that persons with greater amounts of periaortic fat are more likely to have clinical PAD and a low ankle-brachial index.

Methods and results: We quantified periaortic fat surrounding the thoracic aorta using a novel volumetric quantitative approach in 1205 participants from the Framingham Heart Study Offspring cohort (mean age, 65.9 years; women, 54%); visceral abdominal fat also was measured. Clinical peripheral arterial disease was defined as a history of intermittent claudication, and ankle-brachial index was dichotomized as low ( ≤ 0.9) or lower-extremity revascularization versus normal (> 0.9 to < 1.4). Regression models were created to examine the association between periaortic fat and intermittent claudication or low ankle-brachial index (n = 66). In multivariable logistic regression, per 1 SD increase in periaortic fat, the odds ratio for the combined end point was 1.52 (P = 0.004); these results were strengthened with additional adjustment for body mass index (odds ratio, 1.69; P = 0.002) or visceral abdominal fat (odds ratio, 1.67; P = 0.009), whereas no association was observed for visceral abdominal fat (P = 0.16). Similarly, per SD increase in body mass index or waist circumference, no association was observed after accounting for visceral abdominal fat (body mass index, P = 0.35; waist circumference, P=0.49).

Conclusions: Periaortic fat is associated with low ABI and intermittent claudication.

Figure 1

A demonstrates the upper boundaries of peri-aortic fat in an axial CT image, while figure B shows the corresponding 3D reconstruction. Peri-aortic fat, as measured by computed tomography, was defined as any pixel of attenuation between −195 and −45 HU within the region of interest