Abstract
OBJECTIVE: Visceral adiposity is a cardiovascular risk factor, but its role in the development of abdominal aortic aneurysm (AAA) remains unclear. This study primarily assessed the association of visceral adiposity index (VAI) with AAA incidence, and secondarily evaluated its interaction/joint effects with genetic risk, and potential sex differences.</p>
METHODS: This study included 420 069 participants from the UK Biobank. VAI was calculated at baseline (2006 - 2010) using body mass index, waist circumference, triglycerides, and high density lipoprotein cholesterol. Restricted cubic splines (RCS) were applied to examine the association between VAI and the development of AAA, while Cox proportional hazards models estimated adjusted hazard ratios (HRs). Interaction and joint effects of VAI and polygenic risk on AAA risk were also evaluated.</p>
RESULTS: During a follow up of median 13.6 years, there were 2 083 cases of AAA. Fully adjusted models showed that each unit/standard deviation increase in VAI was associated with a 12% and 21% higher AAA risk, respectively. Quartile analysis showed adjusted HR (95% CI) of 1.00 (0.84 - 1.18), 1.14 (0.96 - 1.34), and 1.32 (1.12 - 1.55) for Q2 to Q4 compared with Q1 (p for trend < .001). RCS analysis revealed a sex specific pattern: a linear association between VAI and AAA risk in men, and a non-linear association in women. Threshold analysis revealed that in women with VAI < 1.5, AAA risk decreased by 46% per unit VAI increase (HR 0.54, 95% CI 0.31 - 0.94); above this threshold, risk increased by 19% per unit (HR 1.19, 95% CI 1.09 - 1.29). A combination of high VAI (Q4) and high genetic risk conferred a 2.28 fold higher AAA risk (95% CI 1.70 - 3.70) versus low VAI (Q1) and low genetic risk.</p>
CONCLUSION: Higher visceral adiposity, particularly in combination with genetic susceptibility, is significantly associated with an increased development of AAA in a sex specific and non-linear manner. These findings suggest its potential value for targeted screening strategies.</p>