Abstract
BACKGROUND: The composite dietary antioxidant index (CDAI) is a scoring system designed to assess overall dietary antioxidant capacity and has been associated with a reduced risk of cardiovascular diseases. However, its specific impact on aortic aneurysm and dissection (AA/AD) remains unclear. This study aimed to investigate the associations of CDAI with both the incidence and mortality of AA/AD. METHODS: In this UK Biobank-based study, univariate and multivariate logistic regression models were used to assess the association between CDAI and the incidence of AA/AD, the association of CDAI with mortality was evaluated using Cox proportional hazards models. We employed restricted cubic spline (RCS) analyses to examine potential linear or non-linear relationships between the key nutrient components of the CDAI and the outcomes. Furthermore, mediation analysis was performed to assess the potential mediating effects of selected metabolic indicators. RESULTS: A total of 172,450 participants were included in this study, of whom 1,486 developed AA/AD. Univariate logistic regression analysis revealed a significant inverse association between CDAI and the incidence of AA/AD (OR = 0.93, 95% CI: 0.88-0.99, p = 0.024). A significantly lower risk of AA/AD mortality was observed in participants within the highest quartile of CDAI compared to those in the lowest quartile (HR = 0.83, 95% CI: 0.71-0.96, p = 0.018), based on the Cox regression analysis. RCS analysis indicated a linear relationship between CDAI and the mortality of AA/AD (P for overall < 0.001; P for nonlinear > 0.05). Furthermore, mediation analysis suggested that uric acid, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), and high-density lipoprotein cholesterol (HDL-C) mediated the association between CDAI and AA/AD incidence. CONCLUSION: This study supports the pathogenic role of oxidative stress and inflammation in AA/AD, demonstrating that a higher CDAI is associated with lower incidence and mortality of AA/AD in a UK-based adult population. These findings provide new insights, suggesting that dietary antioxidant intervention could serve as a potential preventive strategy against these conditions.