Composite dietary antioxidant index and abdominal aortic calcification: a national cross-sectional study

Purpose The Composite Dietary Antioxidant Index (CDAI) is a novel, inclusive measure for evaluating the antioxidant potential of diets. We aim to explore the link between the CDAI and abdominal aortic calcification (AAC) in U.S. adults aged >= 40 years. Methods This cross-sectional study collected dietary and AAC data for individuals aged >= 40 years from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) database. The CDAI was calculated using six dietary antioxidants. AAC was evaluated using a semi-quantitative scoring system known as AAC-24, with an AAC score greater than 6 as severe AAC (SAAC). To examine the association between CDAI and AAC, including SAAC, liner/logistic regression analyses and smooth curve fitting were applied. Results A total of 2,640 participants were included in this study, and significant decreases in AAC score and SAAC prevalence were observed with ascending CDAI levels (P < 0.01). After adjusting for confounding factors, a clear link was established between the CDAI and both AAC score (beta = -0.083, 95% CI -0.144-0.022, P = 0.008) and SAAC (OR = 0.883, 95% CI 0.806-0.968, P = 0.008), respectively. Further smooth curve fitting indicated a negative correlation between CDAI and both AAC score and SAAC. Conclusions Dietary antioxidant consumption, as quantified by the CDAI, shows an inverse relationship with AAC risk. Additional longitudinal and intervention studies are essential.