Correlation Between Aortic Adipose Tissue and the Indexed Aortic Diameter According to CT Angiography Findings

Background: Aortic aneurysms are dilatations of the aorta that carry a potential risk of rupture. The most common type is the abdominal aortic aneurysm (AAA), while thoracic aortic aneurysms, particularly those in the ascending part, are also significant. Perivascular adipose tissue is an ectopic fat that affects vessels locally by producing bioactive substances. Additionally, central obesity is associated with local aortic diseases. Objectives: The current study aimed to measure periaortic adipose tissue and evaluate its association with the indexed aortic diameter based on multidetector computed tomography (CT) scan findings. Methods: This retrospective and cross-sectional study was conducted in a tertiary center for cardiovascular diseases, continually recruiting 149 patients who had indications for thoracic and abdominal CT angiography. Patients with serious underlying diseases were excluded. The diameters of the aorta and adipose tissue, as well as Body Mass Index, were measured. Data analysis was performed using chi-square, Fisher exact, independent t-test, and Mann–Whitney test with SPSS software, version 16. Comparisons were performed using chi-square or Fisher exact tests for categorical variables, independent t-test for normally distributed data, and Mann–Whitney test for non-normally distributed data. Results: The study population consisted of 149 patients. The prevalence rates of thoracic aortic aneurysm and AAA were 8.7% and 24.8%, respectively. The prevalence of AAA was significantly higher in males (P = 0.025). Patients with AAA and an abdominal aortic diameter exceeding 30 mm were significantly older than the others (P = 0.003). There was a significant correlation between the fat volume around the aorta and the aortic diameter (P < 0.001, r = 0.504). Additionally, significant relationships were found between age and fat volume around both the thoracic and abdominal aorta (P < 0.001 and P < 0.007, r = 0.379 and r = 0.222, respectively), and between body mass index and fat volume around the abdominal aorta (P = 0.044, r = 0.165). Conclusions: The correlation between the volume of periaortic fat tissue and aortic aneurysms was significant in both the thoracic and abdominal aortae. The volume of periaortic fat in AAA was correlated with indexed values, unlike in thoracic aortic aneurysms. In candidates for aortic CT angiography, meticulous measurement of periaortic adipose tissue provides additional valuable data for optimal management.