Adiposity and the risk of aortic dissection incidence and mortality: results from the UK Biobank, the J-SHC study and a meta-analysis of cohort studies

Few studies have investigated the association between adiposity and risk of aortic dissection and data is lacking on adiposity measures other than body mass index (BMI). We analyzed the association between adiposity and risk of aortic dissection in the UK Biobank, and the Japan Specific Health Checkups (J-SHC) Study, and conducted a meta-analysis of cohort studies to clarify the associations between adiposity and risk of aortic dissection. The analytical cohorts included 496,255 participants in the UK Biobank and 630,841 participants in the J-SHC Study. Multivariable Cox proportional hazards regression models were used to analyze associations between adiposity and risk of aortic dissection. PubMed and Embase were searched for relevant studies up to February 27, 2026. Random effects models were used to calculate summary relative risks (RRs) and 95% confidence intervals (CIs) for the association between adiposity and risk of aortic dissection. In the UK Biobank and J-SHC, there were 371 and 105 aortic dissections during 12.3 and 4 years follow-up, respectively. In the UK Biobank, positive associations (HRs, 95% CIs) were observed between high BMI (1.54, 1.01–2.37, p trend =0.01), waist circumference (1.82, 1.27–2.60, p trend =0.001), hip circumference (1.77, 1.25–2.50, p trend <0.001), waist-to-height ratio (1.88, 1.30–2.70, p trend =0.10), and fat mass (1.36, 0.97–1.91, p trend =0.02) and aortic dissection risk, but no clear association was observed for waist-to-hip ratio (1.28, 0.90–1.81, p trend =0.08) and body fat percentage (1.09, 0.77–1.54, p trend =0.53). In the J-SHC Study, higher BMI (2.36, 0.98–4.84, p trend =0.018), waist circumference (2.26, 1.18–4.60, p trend =0.003), and waist-to-height ratio (2.61, 1.27–5.92, p trend =0.009) were positively associated with aortic dissection mortality. Five cohort studies were included in the meta-analysis on BMI and aortic dissection (2007 cases and 4,962,288 participants). The summary RR per 5 kg/m 2 increment in BMI was 1.09 (1.00-1.20, I 2 = 43%), per 10 cm increment in waist circumference was 1.21 (1.05–1.40, I 2 = 50%, n = 2), and per 0.1 unit increment in waist-to-height ratio was 1.32 (1.08–1.61, I 2 = 39%, n = 2). These findings provide evidence for a positive association between both general and abdominal adiposity and the risk of aortic dissection, with the strongest associations observed for high waist-to-height ratio. Although further large-scale studies are warranted for confirmation, these findings suggest avoiding excess weight may be an important strategy for the prevention of aortic dissection.