Visceral adiposity is not associated with abdominal aortic aneurysm presence and growth

Abstract

Previous studies in rodent models and patients suggest that visceral adipose could play a direct role in the development and progression of abdominal aortic aneurysm (AAA). This study aimed to assess the association of visceral adiposity with AAA presence and growth. This study was a case-control investigation of patients that did (n=196) and did not (n=181) have an AAA who presented to The Townsville Hospital vascular clinic between 2003 and 2012. Cases were patients with AAA (infra-renal aortic diameter >30 mm) and controls were patients with intermittent claudication but no AAA (infra-renal aortic diameter <30 mm). All patients underwent computed tomography angiography (CTA). The visceral to total abdominal adipose volume ratio was estimated from CTAs by assessing total and visceral adipose deposits using an imaging software program. Measurements were assessed for reproducibility by repeat assessments on 15 patients. AAA risk factors were recorded at entry. Forty-five cases underwent two CTAs more than 6 months apart to assess AAA expansion. The association of visceral adiposity with AAA presence and growth was examined using logistic regression. Visceral adipose assessment by CTA was highly reproducible (mean coefficient of variation 1.0%). AAA was positively associated with older age and negatively associated with diabetes. The visceral to total abdominal adipose volume ratio was not significantly associated with AAA after adjustment for other risk factors. Patients with a visceral to total abdominal adipose volume ratio in quartile four had a 1.63-fold increased risk of AAA but with wide confidence intervals (95% CI 0.71-3.70; p=0.248). Visceral adiposity was not associated with AAA growth. In conclusion, this study suggests that visceral adiposity is not specifically associated with AAA presence or growth although larger studies are required to confirm these findings.

High Density of Periaortic Adipose Tissue in Abdominal Aortic Aneurysm

“…7e9 The thoracic aortic PVAT quantity, clinically examined by computed tomography (CT), was found to be positively associated with abdominal aortic calcification 10 and negatively with the ankle brachial index and intermittent claudication. 11 Although the association between visceral adiposity and aortic dilation is conflicting, 12,13 aortic PVAT was positively associated with aortic diameter in individuals from the Framingham Offspring and Third Generation cohorts. 14 This association persisted after adjustment for age, sex, and cardiovascular risk factors including body mass index (BMI) and visceral adipose tissue.…”

Coronary artery disease and abdominal aortic aneurysm growth

“…As outlined in Figure 1, our search identified 20 eligible studies [3][4][5][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] reporting the association of CAD and AAA growth, which included data on a total of 7238 AAA patients. The study design and patient characteristics, detailed measurements of AAA diameters, and growth rates of AAA are summarized in Tables 1, 2, and 3, respectively.…”

“…The study design and patient characteristics, detailed measurements of AAA diameters, and growth rates of AAA are summarized in Tables 1, 2, and 3, respectively. The study design was a randomized controlled trial in three studies, 3,5,21 a prospective cohort study in 11, [14][15][16][17][18]20,22,[25][26][27][28] and a retrospective observational study in six. 4,12,13,19,23,24 Multivariate-adjusted (including propensity-score matched 23 ) estimates were available in seven studies.…”

Role of Adipokines and Perivascular Adipose Tissue in Abdominal Aortic Aneurysm: A Systematic Review and Meta-Analysis of Animal and Human Observational Studies

“…The design of the studies included retrospective, prospective, and longitudinal cohort and case-control studies. All three studies matched the AAA cases and comparators for age and sex (37)(38)(39). In a multicenter retrospective case-control study, comparison of participants with asymptomatic AAA, aortoiliac occlusive disease (AIOD), and healthy controls suggested that AAA was associated with higher PVAT density and the visceral to subcutaneous adipose tissue (VAT/SAT) ratio was significantly greater in AAA patients (37).…”

“…All studies reported the methods used to image the aorta, methods used for aortic diameter assessment and adjusted for potential confounders during analysis (Table 4) (37)(38)(39). Two studies reported the sample size estimate used (37,38). Only one study blinded the observer during analysis of experimental data (37).…”