title: 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.
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia.
authors.forename: Oliver
authors.initials: O
authors.lastname: Cronin
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Liu
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bradshaw
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia School of Medicine and Centre for Clinical Research, University of Queensland, Brisbane, QLD, Australia.
authors.forename: Vikram
authors.initials: V
authors.lastname: Iyer
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, QLD, Australia.
authors.forename: Petra
authors.initials: P
authors.lastname: Buttner
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia.
authors.forename: Margaret
authors.initials: M
authors.lastname: Cunningham
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia School of Medicine and Centre for Clinical Research, University of Queensland, Brisbane, QLD, Australia Department of Vascular Surgery, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Walker
authors.affiliation: Queensland Research Centre for Peripheral Vascular Disease, School of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia Department of Vascular and Endovascular Surgery, The Townsville Hospital, Townsville, QLD, Australia jonathan.golledge@jcu.edu.au.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Golledge
keywords: abdominal aortic aneurysm; adiposity; obesity; visceral